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    Carbohydrate-specific signaling through the DC-SIGN signalosome tailors immunity to Mycobacterium tuberculosis, HIV-1 and Helicobacter pylori. Gringhuis Sonja I,den Dunnen Jeroen,Litjens Manja,van der Vlist Michiel,Geijtenbeek Teunis B H Nature immunology Cooperation between different innate signaling pathways induced by pattern-recognition receptors (PRRs) on dendritic cells (DCs) is crucial for tailoring adaptive immunity to pathogens. Here we show that carbohydrate-specific signaling through the C-type lectin DC-SIGN tailored cytokine production in response to distinct pathogens. DC-SIGN was constitutively associated with a signalosome complex consisting of the scaffold proteins LSP1, KSR1 and CNK and the kinase Raf-1. Mannose-expressing Mycobacterium tuberculosis and human immunodeficiency virus type 1 (HIV-1) induced the recruitment of effector proteins to the DC-SIGN signalosome to activate Raf-1, whereas fucose-expressing pathogens such as Helicobacter pylori actively dissociated the KSR1-CNK-Raf-1 complex from the DC-SIGN signalosome. This dynamic regulation of the signalosome by mannose- and fucose-expressing pathogens led to the enhancement or suppression of proinflammatory responses, respectively. Our study reveals another level of plasticity in tailoring adaptive immunity to pathogens. 10.1038/ni.1778
    Thymic self-reactivity selects natural interleukin 17-producing T cells that can regulate peripheral inflammation. Marks Benjamin R,Nowyhed Heba N,Choi Jin-Young,Poholek Amanda C,Odegard Jared M,Flavell Richard A,Craft Joe Nature immunology Interleukin 17 (IL-17)-producing CD4(+) helper T cells (T(H)-17 cells) share a developmental relationship with Foxp3(+) regulatory T cells (T(reg) cells). Here we show that a T(H)-17 population differentiates in the thymus in a manner influenced by recognition of self antigen and by the cytokines IL-6 and transforming growth factor-beta (TGF-beta). Like previously described T(H)-17 cells, the T(H)-17 cells that developed in the thymus expressed the transcription factor RORgamma t and the IL-23 receptor. These cells also expressed alpha(4)beta(1) integrins and the chemokine receptor CCR6 and were recruited to the lung, gut and liver. In the liver, these cells secreted IL-22 in response to self antigen and mediated host protection during inflammation. Thus, T(H)-17 cells, like T(reg) cells, can be selected by self antigens in the thymus. 10.1038/ni.1783
    The basic leucine zipper transcription factor E4BP4 is essential for natural killer cell development. Gascoyne Duncan M,Long Elaine,Veiga-Fernandes Henrique,de Boer Jasper,Williams Owen,Seddon Benedict,Coles Mark,Kioussis Dimitris,Brady Hugh J M Nature immunology Natural killer (NK) cells are a subset of lymphocytes crucial for innate immunity and modification of adaptive immune responses. In contrast to commitment to the T cell or B cell lineage, little is known about NK cell lineage commitment. Here we show that the basic leucine zipper (bZIP) transcription factor E4BP4 (also called NFIL3) is essential for generation of the NK cell lineage. E4BP4-deficient mice (Nfil3(-/-); called 'E4bp4(-/-)' here) had B cells, T cells and NKT cells but specifically lack NK cells and showed severely impaired NK cell-mediated cytotoxicity. Overexpression of E4bp4 was sufficient to increase NK cell production from hematopoietic progenitor cells. E4BP4 acted in a cell-intrinsic manner 'downstream' of the interleukin 15 receptor (IL-15R) and through the transcription factor Id2. E4bp4(-/-) mice may provide a model for definitive analysis of the contribution of NK cells to immune responses and pathologies. 10.1038/ni.1787
    Mesenchymal stromal cells in bronchoalveolar lavage as predictors of bronchiolitis obliterans syndrome. Badri Linda,Murray Susan,Liu Lyrica X,Walker Natalie M,Flint Andrew,Wadhwa Anish,Chan Kevin M,Toews Galen B,Pinsky David J,Martinez Fernando J,Lama Vibha N American journal of respiratory and critical care medicine RATIONALE:Bronchoalveolar lavage fluid (BAL) from human lung allografts demonstrates the presence of a multipotent mesenchymal stromal cell population. However, the clinical relevance of this novel cellular component of BAL and its association with bronchiolitis obliterans syndrome (BOS), a disease marked by progressive airflow limitation secondary to fibrotic obliteration of the small airways, remains to be determined. OBJECTIVES:In this study we investigate the association of number of mesenchymal stromal cells in BAL with development of BOS in human lung transplant recipients. METHODS:Mesenchymal colony-forming units (CFUs) were quantitated in a cohort of 405 BAL samples obtained from 162 lung transplant recipients. Poisson generalized estimating equations were used to determine the predictors of BAL mesenchymal CFU count. MEASUREMENTS AND MAIN RESULTS:Higher CFU counts were noted early post-transplantation; time from transplant to BAL of greater than 3 months predicted 0.4-fold lower CFU counts (P = 0.0001). BOS diagnosis less than or equal to 365 days before BAL was associated with a 2.11-fold higher CFU count (P = 0.02). There were 2.62- and 2.70-fold higher CFU counts noted in the presence of histologic diagnosis of bronchiolitis obliterans (P = 0.05) and organizing pneumonia (0.0003), respectively. In BAL samples obtained from BOS-free patients greater than 6 months post-transplantation (n = 173), higher mesenchymal CFU counts (≥10) significantly predicted BOS onset in both univariate (hazard ratio, 5.61; 95% CI, 3.03-10.38; P < 0.0001) and multivariate (hazard ratio, 5.02; 95% CI, 2.40-10.51; P < 0.0001) Cox regression analysis. CONCLUSIONS:Measurement of mesenchymal CFUs in the BAL provides predictive information regarding future BOS onset. 10.1164/rccm.201005-0742OC
    A genetic screen for terminator function in yeast identifies a role for a new functional domain in termination factor Nab3. Loya Travis J,O'Rourke Thomas W,Reines Daniel Nucleic acids research The yeast IMD2 gene encodes an enzyme involved in GTP synthesis. Its expression is controlled by guanine nucleotides through a set of alternate start sites and an intervening transcriptional terminator. In the off state, transcription results in a short non-coding RNA that starts upstream of the gene. Transcription terminates via the Nrd1-Nab3-Sen1 complex and is degraded by the nuclear exosome. Using a sensitive terminator read-through assay, we identified trans-acting Terminator Override (TOV) genes that operate this terminator. Four genes were identified: the RNA polymerase II phosphatase SSU72, the RNA polymerase II binding protein PCF11, the TRAMP subunit TRF4 and the hnRNP-like, NAB3. The TOV phenotype can be explained by the loss of function of these gene products as described in models in which termination and RNA degradation are coupled to the phosphorylation state of RNA polymerase II's repeat domain. The most interesting mutations were those found in NAB3, which led to the finding that the removal of merely three carboxy-terminal amino acids compromised Nab3's function. This region of previously unknown function is distant from the protein's well-known RNA binding and Nrd1 binding domains. Structural homology modeling suggests this Nab3 'tail' forms an α-helical multimerization domain that helps assemble it onto an RNA substrate. 10.1093/nar/gks377
    Pan-viral specificity of IFN-induced genes reveals new roles for cGAS in innate immunity. Schoggins John W,MacDuff Donna A,Imanaka Naoko,Gainey Maria D,Shrestha Bimmi,Eitson Jennifer L,Mar Katrina B,Richardson R Blake,Ratushny Alexander V,Litvak Vladimir,Dabelic Rea,Manicassamy Balaji,Aitchison John D,Aderem Alan,Elliott Richard M,García-Sastre Adolfo,Racaniello Vincent,Snijder Eric J,Yokoyama Wayne M,Diamond Michael S,Virgin Herbert W,Rice Charles M Nature The type I interferon (IFN) response protects cells from viral infection by inducing hundreds of interferon-stimulated genes (ISGs), some of which encode direct antiviral effectors. Recent screening studies have begun to catalogue ISGs with antiviral activity against several RNA and DNA viruses. However, antiviral ISG specificity across multiple distinct classes of viruses remains largely unexplored. Here we used an ectopic expression assay to screen a library of more than 350 human ISGs for effects on 14 viruses representing 7 families and 11 genera. We show that 47 genes inhibit one or more viruses, and 25 genes enhance virus infectivity. Comparative analysis reveals that the screened ISGs target positive-sense single-stranded RNA viruses more effectively than negative-sense single-stranded RNA viruses. Gene clustering highlights the cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS, also known as MB21D1) as a gene whose expression also broadly inhibits several RNA viruses. In vitro, lentiviral delivery of enzymatically active cGAS triggers a STING-dependent, IRF3-mediated antiviral program that functions independently of canonical IFN/STAT1 signalling. In vivo, genetic ablation of murine cGAS reveals its requirement in the antiviral response to two DNA viruses, and an unappreciated contribution to the innate control of an RNA virus. These studies uncover new paradigms for the preferential specificity of IFN-mediated antiviral pathways spanning several virus families. 10.1038/nature12862
    Drug delivery with a calixpyrrole--trans-Pt(II) complex. Cafeo Grazia,Carbotti Grazia,Cuzzola Angela,Fabbi Marina,Ferrini Silvano,Kohnke Franz H,Papanikolaou Georgia,Plutino Maria Rosaria,Rosano Camillo,White Andrew J P Journal of the American Chemical Society A meso-p-nitroaniline-calix[4]pyrrole derivative trans-coordinated to a Pt(II) center was synthesized and its structure solved by X-ray analysis. Adenosine monophosphate (AMP) was used as a model compound to evaluate the potential for the assisted delivery of the metal to the DNA nucleobases via the phosphate anion-binding properties of the calix[4]pyrrole unit. An NMR investigation of the kinetics of AMP complexation in the absence of an H-bonding competing solvent (dry CD(3)CN) was consistent with this hypothesis, but we could not detect the interaction of the calix[4]pyrrole with phosphate in the presence of water. However, in vitro tests of the new trans-calixpyrrole-Pt(II) complex on different cancer cell lines indicate a cytotoxic activity that is unquestionably derived from the coexistence of both the trans-Pt(II) fragment and the calix[4]pyrrole unit. 10.1021/ja307791j
    Eosinophil granulocytes are activated during the remission phase of ulcerative colitis. Lampinen M,Rönnblom A,Amin K,Kristjansson G,Rorsman F,Sangfelt P,Säfsten B,Wagner M,Wanders A,Winqvist O,Carlson M Gut AIM:The aim of this study was to establish a method of investigating intestinal eosinophil and neutrophil granulocytes by flow cytometry, and to compare the distribution and activity of these cells in different stages of ulcerative colitis (UC). METHODS:Biopsy samples were taken from six locations of the entire colon and from the terminal ileum in 10 patients with active total UC, 10 patients with inactive total UC, eight patients with active distal UC, and 11 control subjects. Cell suspensions from biopsies and from peripheral blood were incubated with fluorophore conjugated monoclonal antibodies. The use of scatter plot-gating and specific antibodies was established in a flow cytometry assay. RESULTS:Eosinophils were more numerous and more active in patients with active UC than in controls. Interestingly, during inactive UC, the number of activated eosinophils was even larger. Eosinophil activity was high in the rectum of patients with distal colitis but was also slightly elevated in the proximal colon. Neutrophils were increased in number and activity during active but not inactive UC. In patients with distal colitis, activated neutrophils were only found in the sigmoid colon and rectum. CONCLUSION:With this method, we confirm that neutrophils participate in the inflammatory process during active UC, and that they express a resting phenotype during remission. The finding of activated eosinophils in inflamed intestine strengthens the view of these cells as proinflammatory and tissue damaging. Nevertheless, our new finding of high eosinophil activation during inactive UC suggests that eosinophils play a role in repair of injured epithelium. 10.1136/gut.2005.066423
    Progesterone induces human leukocyte antigen-g expression in vascular endothelial and smooth muscle cells. Sheshgiri Rohit,Rao Vivek,Tumiati Laura C,Xiao Rong,Prodger Jessica L,Badiwala Mitesh,Librach Clifford,Delgado Diego H Circulation BACKGROUND:Human leukocyte antigen-G (HLA-G) expression in heart transplant patients has been negatively associated with acute cellular rejection and cardiac allograft vasculopathy. We assessed HLA-G expression in vascular human endothelial and smooth muscle cell cultures to determine if future therapeutic agents can be targeted toward inducing HLA-G expression to protect against allograft rejection and vasculopathy. METHODS AND RESULTS:Human coronary artery endothelial, aortic endothelial, and coronary artery smooth muscle cell cultures were exposed to cytokines (interferon-gamma or interleukin-10), hypoxia/reoxygenation stress, immunosuppressive agents (cyclosporine, sirolimus, or tacrolimus), or progesterone. HLA-G was not expressed by untreated, normoxic cells. Furthermore, maximal doses of interferon-gamma, interleukin-10, cyclosporine, sirolimus, or tacrolimus, as well as exposure to hypoxia/reoxygenation, failed to induce HLA-G expression. HLA-G, which has previously not been detected in adult vascular endothelial and smooth muscle cells, was detected by enzyme-linked immunosorbent assay and flow cytometry in human coronary artery endothelial, human coronary aortic endothelial, and human coronary artery smooth muscle cultures after incubation with progesterone in a dose-dependent manner (P<0.001) with no change in cellular proliferation ability or viability. This effect was partially blocked in the presence of mifepristone, a progesterone receptor antagonist (human coronary artery endothelial: 48.8+/-15.6%; human coronary aortic endothelial: 59.5+/-9.5%; human coronary artery smooth muscle: 59.8+/-9.8% of control; P<0.05). Progesterone-induced HLA-G expression was not protective against hypoxia/reoxygenation injury. CONCLUSIONS:HLA-G is not expressed at baseline in vascular endothelial and smooth muscle cells but can be induced by exposure to progesterone. Although tightly regulated, induction of HLA-G expression in these cells may represent a promising and novel therapeutic strategy to protect against rejection and cardiac allograft vasculopathy after heart transplantation. 10.1161/CIRCULATIONAHA.107.757781
    Toll-like receptor 2 on inflammatory monocytes induces type I interferon in response to viral but not bacterial ligands. Barbalat Roman,Lau Laura,Locksley Richard M,Barton Gregory M Nature immunology Despite the paradigm that the innate immune system uses nucleic acid-specific receptors to detect viruses because of a lack of other conserved features, many viruses are recognized by Toll-like receptor 2 (TLR2) and TLR4. The relevance of this recognition for antiviral immunity remains largely unexplained. Here we report that TLR2 activation by viruses led to the production of type I interferon. TLR2-dependent induction of type I interferon occurred only in response to viral ligands, which indicates that TLR2 is able to discriminate between pathogen classes. We demonstrate that this specialized response was mediated by Ly6C(hi) inflammatory monocytes. Thus, the innate immune system can detect certain non-nucleic acid features of viruses and links this recognition to the induction of specific antiviral genes. 10.1038/ni.1792
    Mapping normal and cancer cell signalling networks: towards single-cell proteomics. Irish Jonathan M,Kotecha Nikesh,Nolan Garry P Nature reviews. Cancer Oncogenesis and tumour progression are supported by alterations in cell signalling. Using flow cytometry, it is now possible to track and analyse signalling events in individual cancer cells. Data from this type of analysis can be used to create a network map of signalling in each cell and to link specific signalling profiles with clinical outcomes. This form of 'single-cell proteomics' can identify pathways that are activated in therapy-resistant cells and can provide biomarkers for cancer diagnosis and for determining patient prognosis. 10.1038/nrc1804
    Identity, regulation and in vivo function of gut NKp46+RORγt+ and NKp46+RORγt- lymphoid cells. Reynders Ana,Yessaad Nadia,Vu Manh Thien-Phong,Dalod Marc,Fenis Aurore,Aubry Camille,Nikitas Georgios,Escalière Bertrand,Renauld Jean Christophe,Dussurget Olivier,Cossart Pascale,Lecuit Marc,Vivier Eric,Tomasello Elena The EMBO journal The gut is a major barrier against microbes and encloses various innate lymphoid cells (ILCs), including two subsets expressing the natural cytotoxicity receptor NKp46. A subset of NKp46(+) cells expresses retinoic acid receptor-related orphan receptor γt (RORγt) and produces IL-22, like lymphoid tissue inducer (LTi) cells. Other NKp46(+) cells lack RORγt and produce IFN-γ, like conventional Natural Killer (cNK) cells. The identity, the regulation and the in vivo functions of gut NKp46(+) ILCs largely remain to be unravelled. Using pan-genomic profiling, we showed here that small intestine (SI) NKp46(+)RORγt(-) ILCs correspond to SI NK cells. Conversely, we identified a transcriptional programme conserved in fetal LTi cells and adult SI NKp46(+)RORγt(+) and NKp46(-)RORγt(+) ILCs. We also demonstrated that the IL-1β/IL-1R1/MyD88 pathway, but not the commensal flora, drove IL-22 production by NKp46(+)RORγt(+) ILCs. Finally, oral Listeria monocytogenes infection induced IFN-γ production in SI NK and IL-22 production in NKp46(+)RORγt(+) ILCs, but only IFN-γ contributed to control bacteria dissemination. NKp46(+) ILC heterogeneity is thus associated with subset-specific transcriptional programmes and effector functions that govern their implication in gut innate immunity. 10.1038/emboj.2011.201
    A yeast BH3-only protein mediates the mitochondrial pathway of apoptosis. The EMBO journal Mitochondrial outer membrane permeabilization is a watershed event in the process of apoptosis, which is tightly regulated by a series of pro- and anti-apoptotic proteins belonging to the BCL-2 family, each characteristically possessing a BCL-2 homology domain 3 (BH3). Here, we identify a yeast protein (Ybh3p) that interacts with BCL-X(L) and harbours a functional BH3 domain. Upon lethal insult, Ybh3p translocates to mitochondria and triggers BH3 domain-dependent apoptosis. Ybh3p induces cell death and disruption of the mitochondrial transmembrane potential via the mitochondrial phosphate carrier Mir1p. Deletion of Mir1p and depletion of its human orthologue (SLC25A3/PHC) abolish stress-induced mitochondrial targeting of Ybh3p in yeast and that of BAX in human cells, respectively. Yeast cells lacking YBH3 display prolonged chronological and replicative lifespans and resistance to apoptosis induction. Thus, the yeast genome encodes a functional BH3 domain that induces cell death through phylogenetically conserved mechanisms. 10.1038/emboj.2011.197
    dysregulation of CD1d-restricted type ii natural killer T cells leads to spontaneous development of colitis in mice. Liao Chia-Min,Zimmer Michael I,Shanmuganad Sharmila,Yu Hon-Tsen,Cardell Susanna L,Wang Chyung-Ru Gastroenterology BACKGROUND & AIMS:CD1d-restricted natural killer (NK) T cells are a subset of immunoregulatory T cells that comprise type I (express the semi-invariant T-cell receptor [TCR] and can be detected using the α-galactosylceramide/CD1d tetramer) and type II (express diverse TCRs and cannot be directly identified). Studies in mouse models of inflammatory bowel disease revealed a complex role for type I NKT cells in the development of colitis. Type II NKT cells have been associated with intestinal inflammation in patients with ulcerative colitis. METHODS:To investigate whether dysregulation of type II NKT cells, caused by increased expression of CD1d, can contribute to colitis, we generated transgenic mice that express high levels of CD1d and a TCR from an autoreactive, type II NKT cell (CD1dTg/24αβTg mice). RESULTS:CD1dTg/24αβTg mice had reduced numbers of 24αβ T cells compared with 24αβTg mice, indicating that negative selection increases among type II NKT cells engaged by abundant self-antigen. The residual 24αβ T cells in CD1dTg/24αβTg mice had an altered surface phenotype and acquired a cytokine profile distinct from that of equivalent cells in 24αβTg mice. Interestingly, CD1dTg/24αβTg mice spontaneously developed colitis; adoptive transfer experiments confirmed that type II NKT cells that develop in the context of increased CD1d expression are pathogenic. CONCLUSIONS:Aberrant type II NKT cell responses directly contribute to intestinal inflammation in mice, indicating the importance of CD1d expression levels in the development and regulation of type II NKT cells. 10.1053/j.gastro.2011.10.030
    B cells contribute to the antitumor activity of CpG-oligodeoxynucleotide in a mouse model of metastatic lung carcinoma. Sorrentino Rosalinda,Morello Silvana,Forte Giovanni,Montinaro Antonella,De Vita Genoveffa,Luciano Antonio,Palma Giuseppe,Arra Claudio,Maiolino Piera,Adcock Ian M,Pinto Aldo American journal of respiratory and critical care medicine RATIONALE:CpG-oligodeoxynucleotide (CpG-ODN; CpG), a Toll-like receptor-9 ligand, has been widely studied as a potential antitumor adjuvant. Toll-like receptor-9 is highly expressed on lung carcinoma tissues and some immune cells, such as plasmacytoid dendritic cells and B cells. OBJECTIVES:The aim of our study was to elucidate the effect of CpG on B cells in a mouse model of lung carcinoma. METHODS:C57Bl/6j, B cell-deficient, and Nude mice were intravenously implanted with the lung metastatic B16-F10 melanoma cells and killed 3 and 7 days after CpG administration. MEASUREMENTS AND MAIN RESULTS:Administration of CpG increased lung tumor growth in B16-F10-implanted C57BL/6J mice. The genetic absence of B cells strongly facilitated CpG-induced tumor progression. In contrast, the adoptive transfer of CpG-activated B cells induced tumor arrest, associated with a reduced suppressive immune environment due to the lower recruitment of regulatory T cells, myeloid-derived suppressor cells, and CD8(+) regulatory T cells along with the reduced expression of suppressive cytokines such as IL-10 and transforming growth factor-β. Furthermore, concomitant with higher production of IFN-γ, the apoptosis rate in the lungs of mice adoptively transferred with CpG-activated B cells was increased. Depletion of mature CD20(+) B cells increased the lung tumor burden in CpG-treated C57BL/6J mice and nude mice. Moreover, nude mice had the same lung tumor burden as B cell-deficient mice when mature CD20(+) B cells were depleted. CONCLUSIONS:Our data demonstrate the protective antitumor activity of CpG-activated B cells and shed light on CpG as an antitumor adjuvant for lung cancer therapy. 10.1164/rccm.201010-1738OC
    Dual Role of IL-22 in allergic airway inflammation and its cross-talk with IL-17A. Besnard Anne-Gaelle,Sabat Robert,Dumoutier Laure,Renauld Jean-Christophe,Willart Monique,Lambrecht Bart,Teixeira Mauro M,Charron Sabine,Fick Lizette,Erard François,Warszawska Katarzyna,Wolk Kerstin,Quesniaux Valerie,Ryffel Bernhard,Togbe Dieudonnée American journal of respiratory and critical care medicine RATIONALE:IL-22 has both proinflammatory and antiinflammatory properties. Its role in allergic lung inflammation has not been explored. OBJECTIVES:To investigate the expression and roles of IL-22 in the onset and resolution of experimental allergic asthma and its cross-talk with IL-17A. METHODS:IL-22 expression was assessed in patient samples and in the lung of mice immunized and challenged with ovalbumin. IL-22 functions in allergic airway inflammation were evaluated using mice deficient in IL-22 or anti-IL-22 neutralizing antibodies. Moreover, the effects of recombinant IL-22 and IL-17A neutralizing antibodies were investigated. MEASUREMENTS AND MAIN RESULTS:Increased pulmonary IL-22 expression is found in the serum of patients with asthma and mice immunized and challenged with ovalbumin. Allergic lung inflammation is IL-22 dependent because eosinophil recruitment, Th2 cytokine including IL-13 and IL-33, chemokine production, airway hyperreactivity, and mucus production are drastically reduced in mice deficient in IL-22 or by IL-22 antibody neutralization during immunization of wild-type mice. By contrast, IL-22 neutralization during antigen challenge enhanced allergic lung inflammation with increased Th2 cytokines. Consistent with this, recombinant IL-22 given with allergen challenge protects mice from lung inflammation. Finally, IL-22 may regulate the expression and proinflammatory properties of IL-17A in allergic lung inflammation. CONCLUSIONS:IL-22 is required for the onset of allergic asthma, but functions as a negative regulator of established allergic inflammation. Our study reveals that IL-22 contributes to the proinflammatory properties of IL-17A in experimental allergic asthma. 10.1164/rccm.201008-1383OC
    Stochastic state transitions give rise to phenotypic equilibrium in populations of cancer cells. Gupta Piyush B,Fillmore Christine M,Jiang Guozhi,Shapira Sagi D,Tao Kai,Kuperwasser Charlotte,Lander Eric S Cell Cancer cells within individual tumors often exist in distinct phenotypic states that differ in functional attributes. While cancer cell populations typically display distinctive equilibria in the proportion of cells in various states, the mechanisms by which this occurs are poorly understood. Here, we study the dynamics of phenotypic proportions in human breast cancer cell lines. We show that subpopulations of cells purified for a given phenotypic state return towards equilibrium proportions over time. These observations can be explained by a Markov model in which cells transition stochastically between states. A prediction of this model is that, given certain conditions, any subpopulation of cells will return to equilibrium phenotypic proportions over time. A second prediction is that breast cancer stem-like cells arise de novo from non-stem-like cells. These findings contribute to our understanding of cancer heterogeneity and reveal how stochasticity in single-cell behaviors promotes phenotypic equilibrium in populations of cancer cells. 10.1016/j.cell.2011.07.026
    Optical trapping of individual human immunodeficiency viruses in culture fluid reveals heterogeneity with single-molecule resolution. Pang Yuanjie,Song Hanna,Kim Jin H,Hou Ximiao,Cheng Wei Nature nanotechnology Optical tweezers use the momentum of photons to trap and manipulate microscopic objects, contact-free, in three dimensions. Although this technique has been widely used in biology and nanotechnology to study molecular motors, biopolymers and nanostructures, its application to study viruses has been very limited, largely due to their small size. Here, using optical tweezers that can simultaneously resolve two-photon fluorescence at the single-molecule level, we show that individual HIV-1 viruses can be optically trapped and manipulated, allowing multi-parameter analysis of single virions in culture fluid under native conditions. We show that individual HIV-1 differs in the numbers of envelope glycoproteins by more than one order of magnitude, which implies substantial heterogeneity of these virions in transmission and infection at the single-particle level. Analogous to flow cytometry for cells, this fluid-based technique may allow ultrasensitive detection, multi-parameter analysis and sorting of viruses and other nanoparticles in biological fluid with single-molecule resolution. 10.1038/nnano.2014.140
    Flow cytometry--biologic and clinical application of a powerful methodology. Holt P R,Koss L G Gastroenterology
    Cigarette Smoke Induces Stem Cell Features of Pancreatic Cancer Cells via PAF1. Nimmakayala Rama Krishna,Seshacharyulu Parthasarathy,Lakshmanan Imayavaramban,Rachagani Satyanarayana,Chugh Seema,Karmakar Saswati,Rauth Sanchita,Vengoji Raghupathy,Atri Pranita,Talmon Geoffrey A,Lele Subodh M,Smith Lynette M,Thapa Ishwor,Bastola Dhundy,Ouellette Michel M,Batra Surinder K,Ponnusamy Moorthy P Gastroenterology BACKGROUND & AIMS:Cigarette smoking is a major risk factor for pancreatic cancer. Aggressive pancreatic tumors contain cancer cells with stem cell features. We investigated whether cigarette smoke induces stem cell features in pancreatic cancer cells. METHODS:Kras; Pdx1-Cre mice were exposed to cigarette smoke or clean air (controls) for up to 20 weeks; pancreata were collected and analyzed by histology, quantitative reverse transcription polymerase chain reaction, and confocal immunofluorescence microscopy. HPNE and Capan1 cells were exposed to cigarette smoke extract (CSE), nicotine and nicotine-derived carcinogens (NNN or NNK), or clean air (controls) for 80 days and evaluated for stem cell markers and features using flow cytometry-based autofluorescence, sphere formation, and immunoblot assays. Proteins were knocked down in cells with small interfering RNAs. We performed RNA sequencing analyses of CSE-exposed cells. We used chromatin immunoprecipitation assays to confirm the binding of FOS-like 1, AP-1 transcription factor subunit (FOSL1) to RNA polymerase II-associated factor (PAF1) promoter. We obtained pancreatic ductal adenocarcinoma (PDAC) and matched nontumor tissues (n = 15) and performed immunohistochemical analyses. RESULTS:Chronic exposure of HPNE and Capan1 cells to CSE caused them to increase markers of stem cells, including autofluorescence and sphere formation, compared with control cells. These cells increased expression of ABCG2, SOX9, and PAF1, via cholinergic receptor nicotinic alpha 7 subunit (CHRNA7) signaling to mitogen-activated protein kinase 1 and FOSL1. CSE-exposed pancreatic cells with knockdown of PAF1 did not show stem cell features. Exposure of cells to NNN and NNK led to increased expression of CHRNA7, FOSL1, and PAF1 along with stem cell features. Pancreata from Kras; Pdx1-Cre mice exposed to cigarette smoke had increased levels of PAF1 mRNA and protein, compared with control mice, as well as increased expression of SOX9. Levels of PAF1 and FOSL1 were increased in PDAC tissues, especially those from smokers, compared with nontumor pancreatic tissue. CSE exposure increased expression of PHD-finger protein 5A, a pluripotent transcription factor and its interaction with PAF1. CONCLUSIONS:Exposure to cigarette smoke activates stem cell features of pancreatic cells, via CHRNA7 signaling and FOSL1 activation of PAF1 expression. Levels of PAF1 are increased in pancreatic tumors of humans and mice with chronic cigarette smoke exposure. 10.1053/j.gastro.2018.05.041
    microRNA 125a Regulates MHC-I Expression on Esophageal Adenocarcinoma Cells, Associated With Suppression of Antitumor Immune Response and Poor Outcomes of Patients. Mari Luigi,Hoefnagel Sanne J M,Zito Domenico,van de Meent Marian,van Endert Peter,Calpe Silvia,Sancho Serra Maria Del Carmen,Heemskerk Mirjam H M,van Laarhoven Hanneke W M,Hulshof Maarten C C M,Gisbertz Susanne S,Medema Jan Paul,van Berge Henegouwen Mark I,Meijer Sybren L,Bergman Jacques J G H M,Milano Francesca,Krishnadath Kausilia K Gastroenterology BACKGROUND & AIMS:Immune checkpoint inhibition may affect growth or progression of highly aggressive cancers, such as esophageal adenocarcinoma (EAC). We investigated the regulation of expression of major histocompatibility complex, class 1 (MHC-I) proteins (encoded by HLA-A, HLA-B, and HLA-C) and the immune response to EACs in patient samples. METHODS:We performed quantitative polymerase chain reaction array analyses of OE33 cells and OE19 cells, which express different levels of the ATP binding cassette subfamily B member 1 (TAP1) and TAP2, required for antigen presentation by MHC-I, to identify microRNAs (miRNAs) that regulate their expression. We performed luciferase assays to validate interactions between miRNAs and potential targets. We overexpressed candidate miRNAs in OE33, FLO-1, and OACP4 C cell lines and performed quantitative polymerase chain reaction, immunoblot, and flow cytometry analyses to identify changes in messenger RNA (mRNA) and protein expression; we studied the effects of cytotoxic T cells. We performed miRNA in situ hybridization, RNA-sequencing, and immunohistochemical analyses of tumor tissues from 51 untreated patients with EAC in the Netherlands. Clinical and survival data were collected for patients, and EAC subtypes were determined. RESULTS:We found OE19 cells to have increased levels of 7 miRNAs. Of these, we found binding sites for miRNA 125a (MIR125a)-5p in the 3' untranslated region of the TAP2 mRNA and binding sites for MIR148a-3p in 3' untranslated regions of HLA-A, HLA-B, and HLA-C mRNAs. Overexpression of these miRNAs reduced expression of TAP2 in OE33, FLO-1, and OACP4 C cells, and reduced cell-surface levels of MHC-I. OE33 cells that expressed the viral peptide BZLF1 were killed by cytotoxic T cells, whereas OE33 that overexpressed MIR125a-5p or MIR 148a along with BZLF1 were not. In EAC and nontumor tissues, levels of MIR125a-5p correlated inversely with levels of TAP2 protein. High expression of TAP1 by EAC correlated with significantly shorter overall survival times of patients. EACs that expressed high levels of TAP1 and genes involved in antigen presentation also expressed high levels of genes that regulate the adaptive immune response, PD-L1, PD-L2, and IDO1; these EACs had a poor response to neoadjuvant chemoradiotherapy and associated with shorter overall survival times of patients. CONCLUSIONS:In studies of EAC cell lines and tumor tissues, we found increased levels of MIR125a-5p and MIR148a-3p to reduce levels of TAP2 and MHC-I, required for antigen presentation. High expression of MHC-I molecules by EAC correlated with markers of an adaptive immune response and significantly shorter overall survival times of patients. 10.1053/j.gastro.2018.06.030
    Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis. Reynolds G,Gibbon J R,Pratt A G,Wood M J,Coady D,Raftery G,Lorenzi A R,Gray A,Filer A,Buckley C D,Haniffa M A,Isaacs J D,Hilkens C M U Annals of the rheumatic diseases OBJECTIVE:A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA. METHODS:Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity). RESULTS:RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB. CONCLUSIONS:We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells. 10.1136/annrheumdis-2014-206578
    Multivariable model for time to first treatment in patients with chronic lymphocytic leukemia. Wierda William G,O'Brien Susan,Wang Xuemei,Faderl Stefan,Ferrajoli Alessandra,Do Kim-Anh,Garcia-Manero Guillermo,Cortes Jorge,Thomas Deborah,Koller Charles A,Burger Jan A,Lerner Susan,Schlette Ellen,Abruzzo Lynne,Kantarjian Hagop M,Keating Michael J Journal of clinical oncology : official journal of the American Society of Clinical Oncology PURPOSE:The clinical course for patients with chronic lymphocytic leukemia (CLL) is diverse; some patients have indolent disease, never needing treatment, whereas others have aggressive disease requiring early treatment. We continue to use criteria for active disease to initiate therapy. Multivariable analysis was performed to identify prognostic factors independently associated with time to first treatment for patients with CLL. PATIENTS AND METHODS:Traditional laboratory, clinical prognostic, and newer prognostic factors such as fluorescent in situ hybridization (FISH), IGHV mutation status, and ZAP-70 expression evaluated at first patient visit to MD Anderson Cancer Center were correlated by multivariable analysis with time to first treatment. This multivariable model was used to develop a nomogram-a weighted tool to calculate 2- and 4-year probability of treatment and estimate median time to first treatment. RESULTS:There were 930 previously untreated patients who had traditional and new prognostic factors evaluated; they did not have active CLL requiring initiation of treatment within 3 months of first visit and were observed for time to first treatment. The following were independently associated with shorter time to first treatment: three involved lymph node sites, increased size of cervical lymph nodes, presence of 17p deletion or 11q deletion by FISH, increased serum lactate dehydrogenase, and unmutated IGHV mutation status. CONCLUSION:We developed a multivariable model that incorporates traditional and newer prognostic factors to identify patients at high risk for progression to treatment. This model may be useful to identify patients for early interventional trials. 10.1200/JCO.2010.33.9002
    Hydroxychloroquine inhibits proinflammatory signalling pathways by targeting endosomal NADPH oxidase. Müller-Calleja Nadine,Manukyan Davit,Canisius Antje,Strand Dennis,Lackner Karl J Annals of the rheumatic diseases OBJECTIVES:Hydroxychloroquine (HCQ) has been used for decades to treat patients with rheumatic diseases, for example, systemic lupus erythematosus (SLE), rheumatoid arthritis or the antiphospholipid syndrome (APS). We hypothesise that HCQ might target endosomal NADPH oxidase (NOX), which is involved in the signal transduction of cytokines as well as antiphospholipid antibodies (aPL). METHODS:For in vitro experiments, monocytic cells were stimulated with tumour necrosis factor α (TNFα), interleukin-1β (IL-1β) or a human monoclonal aPL and the activity of NOX was determined by flow cytometry. The expression of genes known to be induced by these stimuli was quantified by quantitative reverse transcription PCR. Live cell imaging was performed by confocal laser scanning microscopy. Finally, the effects of HCQ on NOX-induced signal transduction were analysed in an in vivo model of venous thrombosis. RESULTS:HCQ strongly reduces or completely prevents the induction of endosomal NOX by TNFα, IL-1β and aPL in human monocytes and MonoMac1 cells. As a consequence, induction of downstream genes by these stimuli is reduced or abrogated. This effect of HCQ is not mediated by direct interference with the agonists but by inhibiting the translocation of the catalytic subunit of NOX2 (gp91phox) into the endosome. In vivo, HCQ protects mice from aPL-induced and NOX2-mediated thrombus formation. CONCLUSIONS:We describe here a novel mechanism of action of HCQ, that is, interference with the assembly of endosomal NOX2. Since endosomal NOX2 is involved in many inflammatory and prothrombotic signalling pathways, this activity of HCQ might explain many of its beneficial effects in rheumatic diseases including the APS. 10.1136/annrheumdis-2016-210012
    Role of Mre11 in chromosomal nonhomologous end joining in mammalian cells. Rass Emilie,Grabarz Anastazja,Plo Isabelle,Gautier Jean,Bertrand Pascale,Lopez Bernard S Nature structural & molecular biology Here we have used an intrachromosomal substrate to monitor the end joining of distant ends, which leads to DNA rearrangements in mammalian cells. We show that silencing Mre11 reduces the efficiency of nonhomologous end joining (NHEJ), affecting both the canonical and alternative pathways, partly in a manner that is independent of the ataxia-telangiectasia mutated kinase (ATM). Silencing of Rad50 or CtIP decreases end-joining efficiency in the same pathway as Mre11. In cells defective for Xrcc4, the MRE11-RAD50-NBS1 (MRN) complex inhibitor MIRIN decreases end-joining frequencies, demonstrating a role for MRN in alternative NHEJ. Consistently, MIRIN sensitizes both complemented and NHEJ-defective cells to ionizing radiation. Conversely, overexpression of Mre11 stimulates the resection of single-stranded DNA and increases alternative end joining, through a mechanism that requires Mre11's nuclease activity, but in an ATM-independent manner. These data demonstrate that, in addition to its role in ATM activation, Mre11 can favor alternative NHEJ through its nuclease activity. 10.1038/nsmb.1641
    Multiple functions of MRN in end-joining pathways during isotype class switching. Dinkelmann Maria,Spehalski Elizabeth,Stoneham Trina,Buis Jeffrey,Wu Yipin,Sekiguchi JoAnn M,Ferguson David O Nature structural & molecular biology The Mre11-Rad50-NBS1 (MRN) complex has many roles in response to DNA double-strand breaks, but its functions in repair by nonhomologous end joining (NHEJ) pathways are poorly understood. We have investigated requirements for MRN in class switch recombination (CSR), a programmed DNA rearrangement in B lymphocytes that requires NHEJ. To this end, we have engineered mice that lack the entire MRN complex in B lymphocytes or that possess an intact complex that harbors mutant Mre11 lacking DNA nuclease activities. MRN deficiency confers a strong defect in CSR, affecting both the classic and the alternative NHEJ pathways. In contrast, absence of Mre11 nuclease activities causes a milder phenotype, revealing a separation of function within the complex. We propose a model in which MRN stabilizes distant breaks and processes DNA termini to facilitate repair by both the classical and alternative NHEJ pathways. 10.1038/nsmb.1639
    CD19(+)CD24(hi)CD38(hi) B cells exhibit regulatory capacity in healthy individuals but are functionally impaired in systemic Lupus Erythematosus patients. Blair Paul A,Noreña Lina Yassin,Flores-Borja Fabian,Rawlings David J,Isenberg David A,Ehrenstein Michael R,Mauri Claudia Immunity The immunosuppressive function of regulatory B cells has been shown in several murine models of chronic inflammation, including collagen-induced arthritis, inflammatory bowel disease, and experimental autoimmune encephalomyelitis. Despite interest in these cells, their relevance to the maintenance of peripheral tolerance in humans remains elusive. Here, we demonstrate that human CD19(+)CD24(hi)CD38(hi) B cells possessed regulatory capacity. After CD40 stimulation, CD19(+)CD24(hi)CD38(hi) B cells suppressed the differentiation of T helper 1 cells, partially via the provision of interleukin-10 (IL-10), but not transforming growth factor-beta (TGF-beta), and their suppressive capacity was reversed by the addition of CD80 and CD86 mAbs. In addition, CD19(+)CD24(hi)CD38(hi) SLE B cells isolated from the peripheral blood of systemic lupus erythematosus (SLE) patients were refractory to further CD40 stimulation, produced less IL-10, and lacked the suppressive capacity of their healthy counterparts. Altered cellular function within this compartment may impact effector immune responses in SLE and other autoimmune disorders. 10.1016/j.immuni.2009.11.009
    Prolonged interleukin-2Ralpha expression on virus-specific CD8+ T cells favors terminal-effector differentiation in vivo. Kalia Vandana,Sarkar Surojit,Subramaniam Shruti,Haining W Nicholas,Smith Kendall A,Ahmed Rafi Immunity CD25, the high-affinity interleukin-2 (IL-2) receptor alpha chain, is rapidly upregulated by antigen-specific CD8(+) T cells after T cell receptor stimulation. Here, we demonstrate that during an acute viral infection, CD25 expression is quite dynamic-after initial upregulation, a subset of virus-specific T cells sustains CD25 expression longer than the rest. At this time when there is distinct heterogeneity in CD25 expression, examination of the in vivo fate of effector cells revealed that CD25(lo) cells, which are relatively less sensitive to IL-2, preferentially upregulate CD127 and CD62L and give rise to functional long-lived memory cells. In contrast, CD25(hi) cells perceiving prolonged IL-2 signals proliferate more rapidly, are prone to apoptosis, exhibit a more pronounced effector phenotype, and appear to be terminally differentiated. Consistent with this, sustained IL-2 receptor signaling during expansion drove terminal-effector differentiation. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal-effector differentiation. 10.1016/j.immuni.2009.11.010
    Protective antifungal memory CD8(+) T cells are maintained in the absence of CD4(+) T cell help and cognate antigen in mice. Nanjappa Som G,Heninger Erika,Wüthrich Marcel,Sullivan Thomas,Klein Bruce The Journal of clinical investigation Individuals who are immunocompromised, including AIDS patients with few CD4(+) T cells, are at increased risk for opportunistic fungal infections. The incidence of such infections is increasing worldwide, meaning that the need for antifungal vaccines is increasing. Although CD4(+) T cells play a dominant role in resistance to many pathogenic fungal infections, we have previously shown that vaccination can induce protective antifungal CD8(+) T cell immunity in the absence of CD4(+) T cells. However, it has not been determined whether vaccine-induced antifungal CD8(+) T cell memory can be maintained in the absence of CD4(+) T cell help. Here, we have shown in a mouse model of vaccination against blastomycosis that antifungal memory CD8(+) T cells are maintained in the absence of CD4(+) T cells without loss of numbers or function for at least 6 months and that the cells protect against infection. Using a system that enabled us to induce and track antigen-specific, antifungal CD8(+) T cells, we found that such cells were maintained for at least 5 months upon transfer into naive mice lacking both CD4(+) T cells and persistent fungal antigen. Additionally, fungal vaccination induced a profile of transcription factors functionally linked with persistent memory in CD8(+) T cells. Thus, unlike bacteria and viruses, fungi elicit long-term CD8(+) T cell memory that is maintained without CD4(+) T cell help or persistent antigen. This has implications for the development of novel antifungal vaccine strategies effective in immunocompromised patients. 10.1172/JCI58762
    Isolation and characterization of resident endogenous c-Kit+ cardiac stem cells from the adult mouse and rat heart. Smith Andrew J,Lewis Fiona C,Aquila Iolanda,Waring Cheryl D,Nocera Aurora,Agosti Valter,Nadal-Ginard Bernardo,Torella Daniele,Ellison Georgina M Nature protocols This protocol describes the isolation of endogenous c-Kit (also known as CD117)-positive (c-Kit(+)), CD45-negative (CD45(-)) cardiac stem cells (eCSCs) from whole adult mouse and rat hearts. The heart is enzymatically digested via retrograde perfusion of the coronary circulation, resulting in rapid and extensive breakdown of the whole heart. Next, the tissue is mechanically dissociated further and cell fractions are separated by centrifugation. The c-Kit(+)CD45(-) eCSC population is isolated by magnetic-activated cell sorting technology and purity and cell numbers are assessed by flow cytometry. This process takes ∼4 h for mouse eCSCs or 4.5 h for rat eCSCs. We also describe how to characterize c-Kit(+)CD45(-) eCSCs. The c-Kit(+)CD45(-) eCSCs exhibit the defining characteristics of stem cells: they are self-renewing, clonogenic and multipotent. This protocol also describes how to differentiate eCSCs into three main cardiac lineages: functional, beating cardiomyocytes, smooth muscle, and endothelial cells. These processes take 17-20 d. 10.1038/nprot.2014.113
    Cxcr2 and Cxcl5 regulate the IL-17/G-CSF axis and neutrophil homeostasis in mice. Mei Junjie,Liu Yuhong,Dai Ning,Hoffmann Christian,Hudock Kristin M,Zhang Peggy,Guttentag Susan H,Kolls Jay K,Oliver Paula M,Bushman Frederic D,Worthen G Scott The Journal of clinical investigation Neutrophils are essential for maintaining innate immune surveillance under normal conditions, but also represent a major contributor to tissue damage during inflammation. Neutrophil homeostasis is therefore tightly regulated. Cxcr2 plays a critical role in neutrophil homeostasis, as Cxcr2(-/-) mice demonstrate mild neutrophilia and severe neutrophil hyperplasia in the bone marrow. The mechanisms underlying these phenotypes, however, are unclear. We report here that Cxcr2 on murine neutrophils inhibits the IL-17A/G-CSF axis that regulates neutrophil homeostasis. Furthermore, enterocyte-derived Cxcl5 in the gut regulates IL-17/G-CSF levels and contributes to Cxcr2-dependent neutrophil homeostasis. Conversely, G-CSF was required for Cxcl5-dependent regulation of neutrophil homeostasis, and inhibition of IL-17A reduced plasma G-CSF concentrations and marrow neutrophil numbers in both Cxcl5(-/-) and Cxcr2(-/-) mice. Cxcr2(-/-) mice constitutively expressed IL-17A and showed increased numbers of IL-17A-producing cells in the lung, terminal ileum, and spleen. Most IL-17-producing splenocytes were responsive to IL-1β plus IL-23 in vitro. Depletion of commensal microbes by antibiotic treatment in Cxcr2(-/-) mice markedly decreased IL-17A and G-CSF expression, neutrophilia, and marrow myeloid hyperplasia. These data suggest a critical role for Cxcr2, Cxcl5, and commensal bacteria in regulation of the IL-17/G-CSF axis and neutrophil homeostasis at mucosal sites and have implications for the development of treatments for pathologies resulting from either excessive or ineffective neutrophil responses. 10.1172/JCI60588
    The receptor SIGIRR suppresses Th17 cell proliferation via inhibition of the interleukin-1 receptor pathway and mTOR kinase activation. Gulen Muhammet F,Kang Zizhen,Bulek Katarzyna,Youzhong Wan,Kim Tae Whan,Chen Yi,Altuntas Cengiz Z,Sass Bak-Jensen Kristian,McGeachy Mandy J,Do Jeong-Su,Xiao Hui,Delgoffe Greg M,Min Booki,Powell Jonathan D,Tuohy Vincent K,Cua Daniel J,Li Xiaoxia Immunity Interleukin-1 (IL-1)-mediated signaling in T cells is essential for T helper 17 (Th17) cell differentiation. We showed here that SIGIRR, a negative regulator of IL-1 receptor and Toll-like receptor signaling, was induced during Th17 cell lineage commitment and governed Th17 cell differentiation and expansion through its inhibitory effects on IL-1 signaling. The absence of SIGIRR in T cells resulted in increased Th17 cell polarization in vivo upon myelin oligodendrocyte glycoprotein (MOG(35-55)) peptide immunization. Recombinant IL-1 promoted a marked increase in the proliferation of SIGIRR-deficient T cells under an in vitro Th17 cell-polarization condition. Importantly, we detected increased IL-1-induced phosphorylation of JNK and mTOR kinase in SIGIRR-deficient Th17 cells compared to wild-type Th17 cells. IL-1-induced proliferation was abolished in mTOR-deficient Th17 cells, indicating the essential role of mTOR activation. Our results demonstrate an important mechanism by which SIGIRR controls Th17 cell expansion and effector function through the IL-1-induced mTOR signaling pathway. 10.1016/j.immuni.2009.12.003
    Interferons direct Th2 cell reprogramming to generate a stable GATA-3(+)T-bet(+) cell subset with combined Th2 and Th1 cell functions. Hegazy Ahmed N,Peine Michael,Helmstetter Caroline,Panse Isabel,Fröhlich Anja,Bergthaler Andreas,Flatz Lukas,Pinschewer Daniel D,Radbruch Andreas,Löhning Max Immunity Current T cell differentiation models invoke separate T helper 2 (Th2) and Th1 cell lineages governed by the lineage-specifying transcription factors GATA-3 and T-bet. However, knowledge on the plasticity of Th2 cell lineage commitment is limited. Here we show that infection with Th1 cell-promoting lymphocytic choriomeningitis virus (LCMV) reprogrammed otherwise stably committed GATA-3(+) Th2 cells to adopt a GATA-3(+)T-bet(+) and interleukin-4(+)interferon-gamma(+) "Th2+1" phenotype that was maintained in vivo for months. Th2 cell reprogramming required T cell receptor stimulation, concerted type I and type II interferon and interleukin-12 signals, and T-bet. LCMV-triggered T-bet induction in adoptively transferred virus-specific Th2 cells was crucial to prevent viral persistence and fatal immunopathology. Thus, functional reprogramming of unfavorably differentiated Th2 cells may facilitate the establishment of protective immune responses. Stable coexpression of GATA-3 and T-bet provides a molecular concept for the long-term coexistence of Th2 and Th1 cell lineage characteristics in single memory T cells. 10.1016/j.immuni.2009.12.004
    Interleukin-2 and inflammation induce distinct transcriptional programs that promote the differentiation of effector cytolytic T cells. Pipkin Matthew E,Sacks Jilian A,Cruz-Guilloty Fernando,Lichtenheld Mathias G,Bevan Michael J,Rao Anjana Immunity Interleukin(IL)-2 and inflammation regulate effector and memory cytolytic T-lymphocyte (CTL) generation during infection. We demonstrate a complex interplay between IL-2 and inflammatory signals during CTL differentiation. IL-2 stimulation induced the transcription factor eomesodermin (Eomes), upregulated perforin (Prf1) transcription, and repressed re-expression of memory CTL markers Bcl6 and IL-7Ralpha. Binding of Eomes and STAT5 to Prf1 cis-regulatory regions correlated with transcriptional initiation (increased recruitment of RNA polymerase II to the Prf1 promoter). Inflammation (CpG, IL-12) enhanced expression of IL-2Ralpha and the transcription factor T-bet, but countered late Eomes and perforin induction while preventing IL-7Ralpha repression by IL-2. After infection of mice with lymphocytic choriomeningitis virus, IL-2Ralpha-deficient effector CD8(+) T cells expressed more Bcl6 but less perforin and granzyme B, formed fewer KLRG-1(+) and T-bet-expressing CTL, and killed poorly. Thus, inflammation influences both effector and memory CTL differentiation, whereas persistent IL-2 stimulation promotes effector at the expense of memory CTL development. 10.1016/j.immuni.2009.11.012
    Th1 memory differentiates recombinant from live herpes zoster vaccines. Levin Myron J,Kroehl Miranda E,Johnson Michael J,Hammes Andrew,Reinhold Dominik,Lang Nancy,Weinberg Adriana The Journal of clinical investigation The adjuvanted varicella-zoster virus (VZV) glycoprotein E (gE) subunit herpes zoster vaccine (HZ/su) confers higher protection against HZ than the live attenuated zoster vaccine (ZV). To understand the immunologic basis for the different efficacies of the vaccines, we compared immune responses to the vaccines in adults 50 to 85 years old. gE-specific T cells were very low/undetectable before vaccination when analyzed by FluoroSpot and flow cytometry. Both ZV and HZ/su increased gE-specific responses, but at peak memory response (PMR) after vaccination (30 days after ZV or after the second dose of HZ/su), gE-specific CD4+ and CD8+ T cell responses were 10-fold or more higher in HZ/su compared with ZV recipients. Comparing the vaccines, T cell memory responses, including gE-IL-2+ and VZV-IL-2+ spot-forming cells (SFCs), were higher in HZ/su recipients and cytotoxic and effector responses were lower. At 1 year after vaccination, all gE-Th1 and VZV-IL-2+ SFCs remained higher in HZ/su compared with ZV recipients. Mediation analyses showed that IL-2+ PMR were necessary for the persistence of Th1 responses to either vaccine and VZV-IL-2+ PMR explained 73% of the total effect of HZ/su on persistence. This emphasizes the biological importance of the memory responses, which were clearly superior in HZ/su compared with ZV participants. 10.1172/JCI121484
    EULAR Scleroderma Trials and Research group statement and recommendations on endothelial precursor cells. Distler J H W,Allanore Y,Avouac J,Giacomelli R,Guiducci S,Moritz F,Akhmetshina A,Walker U A,Gabrielli A,Müller-Ladner U,Tyndall A,Matucci-Cerinic M,Distler O, Annals of the rheumatic diseases Systemic sclerosis (SSc) is characterised by a progressive microangiopathy that contributes significantly to the morbidity of patients with SSc. Besides insufficient angiogenesis, defective vasculogenesis with altered numbers of endothelial precursor cells (EPCs) might also contribute to the vascular pathogenesis of SSc. However, different protocols for isolation, enrichment, culture and quantification of EPCs are currently used, which complicate comparison and interpretation of the results from different studies. The aim of the European League Against Rheumatism Scleroderma Trials and Research (EUSTAR) group expert panel was to provide recommendations for standardisation of future research on EPCs. Consensus statements and recommendations were developed in a face to face meeting by an expert panel of the basic science working group of EUSTAR. The findings were: cardiovascular risk factors and medications such as statins should be described in detail. A detailed description of methods considering isolation, culture, enrichment and detection of EPCs should be given. For in vitro culture of EPCs, no protocol has been shown to be superior to another, but coating with laminin and type IV collagen would resemble most closely the situation in vivo. The endothelial phenotype should be confirmed in all in vitro cultures at the end of the culture period. We recommend using CD133, vascular endothelial growth factor type 2 receptor (VEGFR2) and CD34 in combination with a viability marker for quantification of EPCs in the blood. Finally, exact standard operating procedures for fluorescence-activated cell sorting (FACS) analysis are given that should be strictly followed. In summary, the EUSTAR recommendations will help to unify EPC research and allow better comparison between the results of different studies. 10.1136/ard.2008.091918
    Reciprocal activation between PLK1 and Stat3 contributes to survival and proliferation of esophageal cancer cells. Zhang Yu,Du Xiao-Li,Wang Cheng-Ji,Lin De-Chen,Ruan Xia,Feng Yan-Bin,Huo Yan-Qiu,Peng Haiyong,Cui Jing-Lu,Zhang Tong-Tong,Wang Yong-Quan,Zhang Hongbing,Zhan Qi-Min,Wang Ming-Rong Gastroenterology BACKGROUND & AIMS:Aberrant activation of the signal transducer and activator of transcription (Stat)3 and overexpression of polo-like kinase (PLK)1 each have been associated with cancer pathogenesis. The mechanisms and significance of dysregulation of Stat3 and PLK1 in carcinogenesis and cancer progression are unclear. We investigated the relationship between Stat3 and PLK1 and the effects of their dysregulation in esophageal squamous cell carcinoma (ESCC) cells. METHODS:We used immunoblot, quantitative reverse-transcription polymerase chain reaction, immunochemistry, chromatin immunoprecipitation, mobility shift, and reporter assays to investigate the relationship between Stat3 and PLK1. We used colony formation, fluorescence-activated cell sorting, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, and xenograft tumor assays to determine the effects of increased activation of Stat3 and PLK1 in proliferation and survival of ESCC cells. RESULTS:Stat3 directly activated transcription of PLK1 in esophageal cancer cells and mouse embryonic fibroblast cell NIH3T3. PLK1 then potentiated the expression of Stat3; β-catenin was involved in PLK1-dependent transcriptional activation of Stat3. This mutual regulation between Stat3 and PLK1 was required for proliferation of esophageal cancer cells and resistance to apoptosis in culture and as tumor xenografts in mice. Furthermore, phosphorylation of Stat3 and overexpression of PLK1 were correlated in a subset of ESCC. CONCLUSIONS:Stat3 and PLK1 control each other's transcription in a positive feedback loop that contributes to the development of ESCC. Increased activity of Stat3 and overexpression of PLK1 promote survival and proliferation of ESCC cells in culture and in mice. 10.1053/j.gastro.2011.11.023
    Near-infrared light-responsive core-shell nanogels for targeted drug delivery. Kang Huaizhi,Trondoli Anna Carolina,Zhu Guizhi,Chen Yan,Chang Ya-Jen,Liu Haipeng,Huang Yu-Fen,Zhang Xiaoling,Tan Weihong ACS nano A near-infrared light-responsive drug delivery platform based on Au-Ag nanorods (Au-Ag NRs) coated with DNA cross-linked polymeric shells was constructed. DNA complementarity has been applied to develop a polyacrylamide-based sol-gel transition system to encapsulate anticancer drugs into the gel scaffold. The Au-Ag NR-based nanogels can also be readily functionalized with targeting moieties, such as aptamers, for specific recognition of tumor cells. When exposed to NIR irradiation, the photothermal effect of the Au-Ag NRs leads to a rapid rise in the temperature of the surrounding gel, resulting in the fast release of the encapsulated payload with high controllability. In vitro study confirmed that aptamer-functionalized nanogels can be used as drug carriers for targeted drug delivery with remote control capability by NIR light with high spatial/temporal resolution. 10.1021/nn201171r
    Role of mammalian Mre11 in classical and alternative nonhomologous end joining. Xie Anyong,Kwok Amy,Scully Ralph Nature structural & molecular biology The mammalian Mre11-Rad50-Nbs1 (MRN) complex coordinates double-strand break signaling with repair by homologous recombination and is associated with the H2A.X chromatin response to double-strand breaks, but its role in nonhomologous end joining (NHEJ) is less clear. Here we show that Mre11 promotes efficient NHEJ in both wild-type and Xrcc4(-/-) mouse embryonic stem cells. Depletion of Mre11 reduces the use of microhomology during NHEJ in Xrcc4(+/+) cells and suppresses end resection in Xrcc4(-/-) cells, revealing specific roles for Mre11 in both classical and alternative NHEJ. The NHEJ function of Mre11 is independent of H2A.X. We propose a model in which both enzymatic and scaffolding functions of Mre11 cooperate to support mammalian NHEJ. 10.1038/nsmb.1640
    Expression of CCR6 and CXCR6 by Gut-Derived CD4/CD8α T-Regulatory Cells, Which Are Decreased in Blood Samples From Patients With Inflammatory Bowel Diseases. Godefroy Emmanuelle,Alameddine Joudy,Montassier Emmanuel,Mathé Justine,Desfrançois-Noël Juliette,Marec Nadège,Bossard Céline,Jarry Anne,Bridonneau Chantal,Le Roy Amandine,Sarrabayrouse Guillaume,Kerdreux Elise,Bourreille Arnaud,Sokol Harry,Jotereau Francine,Altare Frédéric Gastroenterology BACKGROUND & AIMS:Faecalibacterium prausnitzii, a member of the Clostridium IV group of the Firmicutes phylum that is abundant in the intestinal microbiota, has anti-inflammatory effects. The relative level of F prausnitzii is decreased in fecal samples from patients with inflammatory bowel diseases (IBDs) compared with healthy individuals. Reduced F prausnitzii was correlated with relapse of Crohn's disease after surgery. We identified, in human colonic mucosa and blood, a population of T regulatory type 1-like T regulatory (T) cells that express CD4 and CD8α (DP8α T cells) and are specific for F prausnitzii. We aimed to determine whether they are altered in patients with IBD. METHODS:We isolated DP8α T cells from human colon lamina propria and blood samples and used flow cytometry to detect markers of cells that are of colon origin. We quantified DP8α cells that express colon-specific markers in blood samples from 106 patients with IBD, 12 patients with infectious colitis, and 35 healthy donors (controls). We identified cells that respond to F prausnitzii. Cells were stimulated with anti-CD3, and their production of interleukin 10 was measured by enzyme-linked immunosorbent assay. We compared the frequency and reactivity of cells from patients vs controls using the 2-sided Student t test or 1-way analysis of variance. RESULTS:Circulating DP8α T cells that proliferate in response to F prausnitzii express the C-C motif chemokine receptor 6 (CCR6) and C-X-C motif chemokine receptor 6 (CXCR6). These cells also have features of T cells, including production of IL-10 and inhibition of T-cell proliferation via CD39 activity. The proportion of circulating CCR6/CXCR6 DP8α T cells was significantly reduced (P < .0001) within the total population of CD3 T cells from patients with IBD compared with patients with infectious colitis or controls. A threshold of <7.875 CCR6/CXCR6 DP8α T cells/10,000 CD3 cells discriminated patients with IBD from those with infectious colitis with 100% specificity and 72.2% sensitivity. CONCLUSIONS:We identified a population of gut-derived T cells that are reduced in blood samples from patients with IBD compared with patients with infectious colitis or controls. These cells should be studied further to determine the mechanisms of this reduction and how it might contribute to the pathogenesis of IBD and their prognostic or diagnostic value. 10.1053/j.gastro.2018.06.078
    Diet Modifies Colonic Microbiota and CD4 T-Cell Repertoire to Induce Flares of Colitis in Mice With Myeloid-Cell Expression of Interleukin 23. Chen Lili,He Zhengxiang,Iuga Alina Cornelia,Martins Filho Sebastião N,Faith Jeremiah J,Clemente Jose C,Deshpande Madhura,Jayaprakash Anitha,Colombel Jean-Frederic,Lafaille Juan J,Sachidanandam Ravi,Furtado Glaucia C,Lira Sergio A Gastroenterology BACKGROUND & AIMS:Several studies have shown that signaling via the interleukin 23 (IL23) receptor is required for development of colitis. We studied the roles of IL23, dietary factors, alterations to the microbiota, and T cells in the development and progression of colitis in mice. METHODS:All mice were maintained on laboratory diet 5053, unless otherwise noted. We generated mice that express IL23 in CX3CR1-positive myeloid cells (R23FR mice) upon cyclic administration of tamoxifen dissolved in diet 2019. Diets 2019 and 5053 have minor differences in the overall composition of protein, fat, fiber, minerals, and vitamins. CX3CR1 mice (FR mice) were used as controls. Some mice were given antibiotics, and others were raised in a germ-free environment. Intestinal tissues were collected and analyzed by histology and flow cytometry. Feces were collected and analyzed by 16S rDNA sequencing. Feces from C57/Bl6, R23FR, or FR mice were fed to FR and R23FR germ-free mice in microbiota transplant experiments. We also performed studies with R23FR/Rag, R23FR/Mu, and R23FR/Tcrd mice. R23FR mice were given injections of antibodies against CD4 or CD8 to deplete T cells. Mesenteric lymph nodes and large intestine CD4 cells from R23FR or FR mice in remission from colitis were transferred into Rag mice. CD4 cells were isolated from donor R23FR mice and recipient Rag mice, and T-cell receptor sequences were determined. RESULTS:Expression of IL23 led to development of a relapsing-remitting colitis that was dependent on the microbiota and CD4 T cells. The relapses were caused by switching from the conventional diet used in our facility (diet 5053) to the diet 2019 and were not dependent on tamoxifen after the first cycle. The switch in the diet modified the microbiota but did not alter levels of IL23 in intestinal tissues compared with mice that remained on the conventional diet. Mesenteric lymph nodes and large intestine CD4 cells from R23FR mice in remission, but not from FR mice, induced colitis after transfer into Rag mice, but only when these mice were placed on the diet 2019. The CD4 T-cell receptor repertoire of Rag mice with colitis (fed the 2019 diet) was less diverse than that from donor mice and Rag mice without colitis (fed the 5053 diet) because of expansion of dominant T-cell clones. CONCLUSIONS:We developed mice that express IL23 in CX3CR1-positive myeloid cells (R23FR mice) and found that they are more susceptible to diet-induced colitis than mice that do not express IL23. The R23FR mice have a population of CD4 T cells that becomes activated in response to dietary changes and alterations to the intestinal microbiota. The results indicate that alterations in the diet, intestinal microbiota, and IL23 signaling can contribute to pathogenesis of inflammatory bowel disease. 10.1053/j.gastro.2018.06.034
    14-3-3η is a novel growth-promoting and angiogenic factor in hepatocellular carcinoma. Shen Jian,Jiang Fei,Yang Ye,Huang Guangming,Pu Fuxing,Liu Qinqiang,Chen Lijun,Ju Liang,Lu Ming,Zhou Fei,Zhang Chi,Luo Xiagang,Yang Xiaojun,Jiao Chengyu,Li Xiangcheng,Li Zhong,Li Yuan,Zhang Jianping Journal of hepatology BACKGROUND & AIMS:Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. The continued search for novel therapeutic strategies for HCC is urgently required. In this study, we aimed to investigate the functions and clinical significance of 14-3-3η protein in HCC. METHODS:Expressions of genes and proteins were determined by quantitative reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry. Their functions were assessed by endothelial cell recruitment, tube formation, wound healing, flow cytometry, immunostaining, immunoprecipitation, and xenograft assay. A tissue microarray followed by univariate and multivariate analyses was performed to indicate the clinical significance. RESULTS:In HCC specimens, overexpression of 14-3-3η was observed not only in tumors but also in intratumoral vessels. In HCC and vascular endothelial cells, 14-3-3η stimulated proliferation and angiogenesis, but attenuated the functions of sorafenib. Briefly, 14-3-3η facilitated the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). Then, by binding to the phosphorylated-ERK1/2 (p-ERK1/2), formed a functional positive feed-back loop. A xenograft model showed that, blockage of either 14-3-3η or ERK1/2 inhibited the tumor growth. Finally, tissue microarray analyses showed that overexpression of 14-3-3η, either in tumors or intratumoral vessels, contributed to the poor survival. CONCLUSIONS:The 14-3-3η-ERK1/2 feedback loop played a characteristic growth-promoting role in HCC, not only in tumors but also in intratumoral vessels. Further, 14-3-3η could be a potential therapeutic target for HCC and a biomarker for predicting sorafenib treatment response. LAY SUMMARY:Here we found that, 14-3-3η protein exhibited a characteristic growth-promoting effect in both tumor and intratumoral vessels of hepatocellular carcinoma by interacting with ERK1/2 signaling. 10.1016/j.jhep.2016.05.017
    Role of beta7 integrin and the chemokine/chemokine receptor pair CCL25/CCR9 in modeled TNF-dependent Crohn's disease. Apostolaki Maria,Manoloukos Menelaos,Roulis Manolis,Wurbel Marc-André,Müller Werner,Papadakis Konstantinos A,Kontoyiannis Dimitris L,Malissen Bernard,Kollias George Gastroenterology BACKGROUND & AIMS:In the present work, we address the requirement for intestinal-specific homing molecules, the chemokine/chemokine receptor pair CCL25/CCR9 and beta7 integrin, in the pathogenesis of the CD8(+) T cell-dependent Tnf(DeltaARE) mouse model of Crohn's-like inflammatory bowel disease. METHODS:We investigated by flow cytometry lymphocyte recruitment in the intestinal epithelium and lamina propria (LP); cytokine production by intraepithelial and LP lymphocytes; and peripheral expression of CCR9, alpha4beta7, and alphaEbeta7 integrin. The functional significance of CCL25/CCR9 and beta7 integrin in inflammatory lymphocyte recruitment and intestinal disease development was assessed in Tnf(DeltaARE) mice genetically lacking these molecules. RESULTS:Intestinal inflammation in the Tnf(DeltaARE) mice is associated with early reduction of CD8alphaalpha-expressing intraepithelial lymphocytes, decreased T helper cell 1 and increased T helper cell 17 responses by LP CD4(+) lymphocytes, increased alphaEbeta7 integrin expression in peripheral activated/memory intestinal-homing CD8alphabeta lymphocytes, and predominance of tumor necrosis factor/interferon-gamma-producing CD8alphabeta lymphocytes in the epithelium. Although CCL25/CCR9 have been strongly implicated in T-lymphocyte recruitment to the small intestine, inflammatory pathology develops unperturbed in the genetic absence of CCL25/CCR9. Furthermore, CD8alphabeta lymphocyte recruitment in the intestinal epithelium and inflammatory infiltration in the LP are not impaired in CCR9- or CCL25-deficient Tnf(DeltaARE) mice. In contrast, genetic ablation of beta7 integrin results in complete amelioration of intestinal pathology. CONCLUSIONS:Our findings demonstrate that development of intestinal inflammation in the Tnf(DeltaARE) mice is critically dependent on beta7 integrin-mediated T-lymphocyte recruitment, whereas the function of the CCL25/CCR9 axis appears dispensable in this model. 10.1053/j.gastro.2008.02.085
    Functional restoration of HCV-specific CD8 T cells by PD-1 blockade is defined by PD-1 expression and compartmentalization. Nakamoto Nobuhiro,Kaplan David E,Coleclough Jennifer,Li Yun,Valiga Mary E,Kaminski Mary,Shaked Abraham,Olthoff Kim,Gostick Emma,Price David A,Freeman Gordon J,Wherry E John,Chang Kyong-Mi Gastroenterology BACKGROUND & AIMS:The immunoinhibitory receptor programmed death-1 (PD-1) is up-regulated on dysfunctional virus-specific CD8 T cells during chronic viral infections, and blockade of PD-1/PD-ligand (PD-L) interactions can restore their function. As hepatitis C virus (HCV) persists in the liver with immune-mediated disease pathogenesis, we examined the role of PD-1/PD-L pathway in antigen-specific CD8 T-cell dysfunction in the liver and blood of HCV-infected patients. METHODS:PD-1 expression and function of circulating CD8 T cells specific for HCV, Epstein-Barr virus, and influenza virus were examined ex vivo and following antigenic stimulation in vitro in patients with acute, chronic, and resolved HCV infection using class I tetramers and flow cytometry. Intrahepatic CD8 T cells were examined from liver explants of chronically HCV-infected transplant recipients. RESULTS:Intrahepatic HCV-specific CD8 T cells from chronically HCV-infected patients were highly PD-1 positive, profoundly dysfunctional, and unexpectedly refractory to PD-1/PD-L blockade, contrasting from circulating PD-1-intermediate HCV-specific CD8 T cells with responsiveness to PD-1/PD-L blockade. This intrahepatic functional impairment was HCV-specific and directly associated with the level of PD-1 expression. Highly PD-1-positive intrahepatic CD8 T cells were more phenotypically exhausted with increased cytotoxic T-lymphocyte antigen 4 and reduced CD28 and CD127 expression, suggesting that active antigen-specific stimulation in the liver induces a profound functional exhaustion not reversible by PD-1/PD-L blockade alone. CONCLUSIONS:HCV-specific CD8 T-cell dysfunction and responsiveness to PD-1/PD-L blockade are defined by their PD-1 expression and compartmentalization. These findings provide new and clinically relevant insight to differential antigen-specific CD8 T-cell exhaustion and their functional restoration. 10.1053/j.gastro.2008.02.033
    SSEA-1 is an enrichment marker for tumor-initiating cells in human glioblastoma. Son Myung Jin,Woolard Kevin,Nam Do-Hyun,Lee Jeongwu,Fine Howard A Cell stem cell CD133+ populations of human glioblastoma multiforme (GBM) cells are reportedly enriched for tumor stem cells (TSCs) or tumor-initiating cells (TICs). Approximately 40% of freshly isolated GBM specimens, however, do not contain CD133+ tumor cells, raising the possibility that CD133 may not be a universal enrichment marker for GBM TSCs/TICs. Here we demonstrate that stage-specific embryonic antigen 1(SSEA-1/LeX)+ GBM cells fulfill the functional criteria for TSC/TIC, since (1) SSEA-1+ cells are highly tumorigenic in vivo, unlike SSEA-1- cells; (2) SSEA-1+ cells can give rise to both SSEA-1+ and SSEA-1- cells, thereby establishing a cellular hierarchy; and (3) SSEA-1+ cells have self-renewal and multilineage differentiation potentials. A distinct subpopulation of SSEA-1+ cells was present in all but one of the primary GBMs examined (n = 24), and most CD133+ tumor cells were also SSEA-1+, suggesting that SSEA-1 may be a general TSC/TIC enrichment marker in human GBMs. 10.1016/j.stem.2009.03.003
    Detection of HIV-1 DNA and messenger RNA in individual cells by PCR-driven in situ hybridization and flow cytometry. Patterson B K,Till M,Otto P,Goolsby C,Furtado M R,McBride L J,Wolinsky S M Science (New York, N.Y.) Human immunodeficiency virus type-1 (HIV-1) DNA and messenger RNA sequences in both cell lines and blood obtained directly from HIV-1-infected patients were amplified by polymerase chain reaction and hybridized to fluorescein-labeled probes in situ, and the individually labeled cells were analyzed by flow cytometry. After flow cytometric analysis, heterogeneous cell populations were reproducibly resolved into HIV-1-positive and -negative distributions. Fluorescence microscopy showed that the cellular morphology was preserved and intracellular localization of amplified product DNA was maintained. Retention of nonspecific probe was not observed. Analysis of proviral DNA and viral messenger RNA in cells in the blood of HIV-1-infected patients showed that the HIV-1 genome persists in a large reservoir of latently infected cells. With the use of this technique it is now possible to detect single-copy DNA or low-abundance messenger RNA rapidly and reproducibly in a minor subpopulation of cells in suspension at single-cell resolution and to sort those cells for further characterization. 10.1126/science.8493534
    Somatic Mutations in and Severe Adult-Onset Autoinflammatory Disease. Beck David B,Ferrada Marcela A,Sikora Keith A,Ombrello Amanda K,Collins Jason C,Pei Wuhong,Balanda Nicholas,Ross Daron L,Ospina Cardona Daniela,Wu Zhijie,Patel Bhavisha,Manthiram Kalpana,Groarke Emma M,Gutierrez-Rodrigues Fernanda,Hoffmann Patrycja,Rosenzweig Sofia,Nakabo Shuichiro,Dillon Laura W,Hourigan Christopher S,Tsai Wanxia L,Gupta Sarthak,Carmona-Rivera Carmelo,Asmar Anthony J,Xu Lisha,Oda Hirotsugu,Goodspeed Wendy,Barron Karyl S,Nehrebecky Michele,Jones Anne,Laird Ryan S,Deuitch Natalie,Rowczenio Dorota,Rominger Emily,Wells Kristina V,Lee Chyi-Chia R,Wang Weixin,Trick Megan,Mullikin James,Wigerblad Gustaf,Brooks Stephen,Dell'Orso Stefania,Deng Zuoming,Chae Jae J,Dulau-Florea Alina,Malicdan May C V,Novacic Danica,Colbert Robert A,Kaplan Mariana J,Gadina Massimo,Savic Sinisa,Lachmann Helen J,Abu-Asab Mones,Solomon Benjamin D,Retterer Kyle,Gahl William A,Burgess Shawn M,Aksentijevich Ivona,Young Neal S,Calvo Katherine R,Werner Achim,Kastner Daniel L,Grayson Peter C The New England journal of medicine BACKGROUND:Adult-onset inflammatory syndromes often manifest with overlapping clinical features. Variants in ubiquitin-related genes, previously implicated in autoinflammatory disease, may define new disorders. METHODS:We analyzed peripheral-blood exome sequence data independent of clinical phenotype and inheritance pattern to identify deleterious mutations in ubiquitin-related genes. Sanger sequencing, immunoblotting, immunohistochemical testing, flow cytometry, and transcriptome and cytokine profiling were performed. CRISPR-Cas9-edited zebrafish were used as an in vivo model to assess gene function. RESULTS:We identified 25 men with somatic mutations affecting methionine-41 (p.Met41) in UBA1, the major E1 enzyme that initiates ubiquitylation. (The gene lies on the X chromosome.) In such patients, an often fatal, treatment-refractory inflammatory syndrome develops in late adulthood, with fevers, cytopenias, characteristic vacuoles in myeloid and erythroid precursor cells, dysplastic bone marrow, neutrophilic cutaneous and pulmonary inflammation, chondritis, and vasculitis. Most of these 25 patients met clinical criteria for an inflammatory syndrome (relapsing polychondritis, Sweet's syndrome, polyarteritis nodosa, or giant-cell arteritis) or a hematologic condition (myelodysplastic syndrome or multiple myeloma) or both. Mutations were found in more than half the hematopoietic stem cells, including peripheral-blood myeloid cells but not lymphocytes or fibroblasts. Mutations affecting p.Met41 resulted in loss of the canonical cytoplasmic isoform of UBA1 and in expression of a novel, catalytically impaired isoform initiated at p.Met67. Mutant peripheral-blood cells showed decreased ubiquitylation and activated innate immune pathways. Knockout of the cytoplasmic UBA1 isoform homologue in zebrafish caused systemic inflammation. CONCLUSIONS:Using a genotype-driven approach, we identified a disorder that connects seemingly unrelated adult-onset inflammatory syndromes. We named this disorder the VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. (Funded by the NIH Intramural Research Programs and the EU Horizon 2020 Research and Innovation Program.). 10.1056/NEJMoa2026834
    Macrophage CD31 Signaling in Dissecting Aortic Aneurysm. Andreata Francesco,Syvannarath Varouna,Clement Marc,Delbosc Sandrine,Guedj Kevin,Fornasa Giulia,Khallou-Laschet Jamila,Morvan Marion,Even Guillaume,Procopio Emanuele,Gaston Anh-Thu,Le Borgne Marie,Deschamps Lydia,Nicoletti Antonino,Caligiuri Giuseppina Journal of the American College of Cardiology BACKGROUND:The authors recently found that a CD31 agonist peptide reaches macrophages in injured aortas and exerts beneficial effects on apolipoprotein E-knockout (Apo E) mice subjected to angiotensin (Ang) II infusion, a model of experimental acute aortic dissection and intramural hematoma (ADIM). OBJECTIVES:The purpose of this study was to evaluate the therapeutic potential of a drug-suitable agonist peptide in experimental ADIM. METHODS:P8RI, a retro-inverso sequence of the best candidate identified by functional in vitro screening of a peptide library, passed an absorption, distribution, metabolism, excretion and toxicology analysis. Apo E mice (male, 28-week-old) implanted with Ang II-releasing pumps received P8RI (2.5 mg/kg/day) or vehicle from day 14 (n = 10/group). Leukocytes were analyzed by flow cytometry. Healing features of human and mouse dissected aortic segments were assessed by histology and immunofluorescence. The effect of CD31 on macrophages was evaluated using cells from CD31 mice and P8RI, in vitro. RESULTS:Human and experimental ADIM were characterized by the infiltration of proinflammatory macrophages. The absence of CD31 enhanced the proinflammatory polarization of macrophages, whereas the CD31 agonist P8RI favored reparative macrophages both in vitro and in vivo. The administration of P8RI after the occurrence of ADIM prevented aneurysmal transformation by promoting the resolution of intramural hematoma and the production of collagen in dissected aortas in vivo, associated with enrichment of M2 macrophages at the site of injury. CONCLUSIONS:CD31 signaling promotes the switching of proinflammatory macrophages to the reparative phenotype and favors the healing of experimental dissected aortas. Treatment with a drug-suitable CD31 agonist may facilitate the clinical management of ADIM. 10.1016/j.jacc.2018.04.047
    Th17 lymphocytes traffic to the central nervous system independently of α4 integrin expression during EAE. Rothhammer Veit,Heink Sylvia,Petermann Franziska,Srivastava Rajneesh,Claussen Malte C,Hemmer Bernhard,Korn Thomas The Journal of experimental medicine The integrin α4β1 (VLA-4) is used by encephalitogenic T cells to enter the central nervous system (CNS). However, both Th1 and Th17 cells are capable of inducing experimental autoimmune encephalomyelitis (EAE), and the molecular cues mediating the infiltration of Th1 versus Th17 cells into the CNS have not yet been defined. We investigated how blocking of α4 integrins affected trafficking of Th1 and Th17 cells into the CNS during EAE. Although antibody-mediated inhibition of α4 integrins prevented EAE when MOG(35-55)-specific Th1 cells were adoptively transferred, Th17 cells entered the brain, but not the spinal cord parenchyma, irrespective of α4 blockade. Accordingly, T cell-conditional α4-deficient mice were not resistant to actively induced EAE but showed an ataxic syndrome with predominantly supraspinal infiltrates of IL-23R(+)CCR6(+)CD4(+) T cells. The entry of α4-deficient Th17 cells into the CNS was abolished by blockade of LFA-1 (αLβ2 integrin). Thus, Th1 cells preferentially infiltrate the spinal cord via an α4 integrin-mediated mechanism, whereas the entry of Th17 cells into the brain parenchyma occurs in the absence of α4 integrins but is dependent on the expression of αLβ2. These observations have implications for the understanding of lesion localization, immunosurveillance, and drug design in multiple sclerosis. 10.1084/jem.20110434
    Type I interferon negatively controls plasmacytoid dendritic cell numbers in vivo. Swiecki Melissa,Wang Yaming,Vermi William,Gilfillan Susan,Schreiber Robert D,Colonna Marco The Journal of experimental medicine Plasmacytoid dendritic cells (pDCs) specialize in the secretion of type I interferons (IFN-I) and thus are considered critical mediators of antiviral responses. We recently reported that pDCs have a very early but limited and transient capacity to curtail viral infections. Additionally, pDC numbers are not sustained in human infections caused by Hepatitis B or C viruses (HBV and HCV) and HIV. Thus, the numbers and/or function of pDCs appear to be regulated during the course of viral infection. In this study, we show that splenic pDCs are reduced in vivo during several systemic viral infections and after administration of synthetic toll-like receptor ligands. We demonstrate that IFN-I, regardless of the source, contributes to this decline and mediates pDC death via the intrinsic apoptosis pathway. These findings demonstrate a feedback control mechanism by which IFN-I modulates pDC numbers, thus fine-tuning systemic IFN-I response to viruses. IFN-I-mediated control of pDCs may explain the loss of pDCs during human infections caused by HBV, HCV, or HIV and has important therapeutic implications for settings in which IFN-I is used to treat infections and autoimmune diseases. 10.1084/jem.20110654
    Highly potent human hematopoietic stem cells first emerge in the intraembryonic aorta-gonad-mesonephros region. Ivanovs Andrejs,Rybtsov Stanislav,Welch Lindsey,Anderson Richard A,Turner Marc L,Medvinsky Alexander The Journal of experimental medicine Hematopoietic stem cells (HSCs) emerge during embryogenesis and maintain hematopoiesis in the adult organism. Little is known about the embryonic development of human HSCs. We demonstrate that human HSCs emerge first in the aorta-gonad-mesonephros (AGM) region, specifically in the dorsal aorta, and only later appear in the yolk sac, liver, and placenta. AGM region cells transplanted into immunodeficient mice provide long-term high level multilineage hematopoietic repopulation. Human AGM region HSCs, although present in low numbers, exhibit a very high self-renewal potential. A single HSC derived from the AGM region generates at least 300 daughter HSCs in primary recipients, which disseminate throughout the entire recipient bone marrow and are retransplantable. These findings highlight the vast regenerative potential of the earliest human HSCs and set a new standard for in vitro generation of HSCs from pluripotent stem cells for the purpose of regenerative medicine. 10.1084/jem.20111688
    Follicular dendritic cells help establish follicle identity and promote B cell retention in germinal centers. Wang Xiaoming,Cho Bryan,Suzuki Kazuhiro,Xu Ying,Green Jesse A,An Jinping,Cyster Jason G The Journal of experimental medicine Follicular dendritic cells (FDCs) retain and display opsonized antigens in primary follicles and germinal centers (GCs). However, their roles beyond antigen presentation have been incompletely defined. In this study, we tested the impact of selective FDC ablation on short-term follicle and GC function. Within 2 d of FDC ablation, primary follicles lost their homogeneity and became disorganized bands of cells around T zones. These B cell areas retained CXCL13-expressing stromal cells but often exhibited inappropriate ER-TR7 and CCL21 expression. Ablation of GC FDCs led to the disappearance of GCs. When B cell death was prevented using a Bcl2 transgene, FDC ablation led to splenic GC B cell dispersal. Mesenteric lymph node GCs were more resistant but became dispersed when sphingosine-1-phosphate receptor-2 was also removed. These experiments indicate that FDCs help maintain primary follicles as a B cell exclusive niche and define a critical role for FDCs in cell retention within GCs. 10.1084/jem.20111449
    Evi1 is essential for hematopoietic stem cell self-renewal, and its expression marks hematopoietic cells with long-term multilineage repopulating activity. Kataoka Keisuke,Sato Tomohiko,Yoshimi Akihide,Goyama Susumu,Tsuruta Takako,Kobayashi Hiroshi,Shimabe Munetake,Arai Shunya,Nakagawa Masahiro,Imai Yoichi,Kumano Keiki,Kumagai Katsuyoshi,Kubota Naoto,Kadowaki Takashi,Kurokawa Mineo The Journal of experimental medicine Ecotropic viral integration site 1 (Evi1), a transcription factor of the SET/PR domain protein family, is essential for the maintenance of hematopoietic stem cells (HSCs) in mice and is overexpressed in several myeloid malignancies. Here, we generate reporter mice in which an internal ribosome entry site (IRES)-GFP cassette is knocked-in to the Evi1 locus. Using these mice, we find that Evi1 is predominantly expressed in long-term HSCs (LT-HSCs) in adult bone marrow, and in the hematopoietic stem/progenitor fraction in the aorta-gonad-mesonephros, placenta, and fetal liver of embryos. In both fetal and adult hematopoietic systems, Evi1 expression marks cells with long-term multilineage repopulating activity. When combined with conventional HSC surface markers, sorting according to Evi1 expression markedly enhances purification of cells with HSC activity. Evi1 heterozygosity leads to marked impairment of the self-renewal capacity of LT-HSCs, whereas overexpression of Evi1 suppresses differentiation and boosts self-renewal activity. Reintroduction of Evi1, but not Mds1-Evi1, rescues the HSC defects caused by Evi1 heterozygosity. Thus, in addition to documenting a specific relationship between Evi1 expression and HSC self-renewal activity, these findings highlight the utility of Evi1-IRES-GFP reporter mice for the identification and sorting of functional HSCs. 10.1084/jem.20110447
    IGSF4 is a novel TCR ζ-chain-interacting protein that enhances TCR-mediated signaling. Kim Hye-Ran,Jeon Byeong-Hun,Lee Hyun-Su,Im Sin-Hyeog,Araki Masatake,Araki Kimi,Yamamura Ken-ichi,Choi Suck-Chei,Park Do-Sim,Jun Chang-Duk The Journal of experimental medicine Immunoglobulin superfamily member 4 (IGSF4) is a known ligand of CRTAM, a receptor expressed in activated NKT and CD8(+) T cells, but its function in T cell immunity has not been elucidated. In this study, we show that IGSF4 directly interacts with the T cell receptor (TCR) ζ-chain and enhances TCR signaling by enhancing ζ-chain phosphorylation. Ectopic overexpression of IGSF4 enhances TCR-mediated T cell activation. In contrast, IGSF4 knockdown shows a dramatic decrease in markers associated with T cell activation compared with those in control small interfering RNA. The transmembrane domain is essential for TCR ζ-chain association and clustering to the immunological synapse, and the ectodomain is associated with T cell interaction with antigen-presenting cells (APCs). IGSF4-deficient mice have impaired TCR-mediated thymocyte selection and maturation. Furthermore, these mice reveal attenuated effector T cell functions accompanied by defective TCR signaling. Collectively, the results indicate that IGSF4 plays a central role in T cell functioning by dual independent mechanisms, control of TCR signaling and control of T cell-APC interaction. 10.1084/jem.20110853
    Rapid sizing of individual fluorescently stained DNA fragments by flow cytometry. Goodwin P M,Johnson M E,Martin J C,Ambrose W P,Marrone B L,Jett J H,Keller R A Nucleic acids research Large, fluorescently stained restriction fragments of lambda phage DNA are sized by passing individual fragments through a focused continuous wave laser beam in an ultrasensitive flow cytometer at a rate of 60 fragments per second. The size of the fluorescence burst emitted by each stained DNA fragment, as it passes through the laser beam, is measured in one millisecond. One hundred sixty four seconds of fluorescence burst data allow linear sizing of DNA with an accuracy of better than two percent over a range of 10 to 50 kbp. This corresponds to analyzing less than 1 pg of DNA. Sizing of DNA fragments by this approach is much faster, requires much less DNA, and can potentially analyze large fragments with better resolution and accuracy than with gel-based electrophoresis. 10.1093/nar/21.4.803
    Multifunctional dendronized peptide polymer platform for safe and effective siRNA delivery. Zeng Hanxiang,Little Hannah C,Tiambeng Timothy N,Williams Gregory A,Guan Zhibin Journal of the American Chemical Society In this study, we designed and synthesized a biodegradable dendronized polypeptide (denpol) platform for delivery of small interfering RNA (siRNA). The novel denpol architecture combines the multivalency of dendrimers and conformational flexibility of linear polymers for optimal siRNA binding. Multifunctional amino acids were incorporated onto the dendrons and the structure was tuned both systematically and combinatorially to select optimal vectors. By screening a focused library, we identified several denpols that can effectively deliver siRNA to NIH 3T3 cells in vitro and exhibit minimal toxicity. For comparison, the best-performing denpol showed significantly improved transfection efficiency over Lipofectamine in serum-containing media. Fluorescence intracellular trafficking studies indicated that amphiphilicity is important for cell uptake and that the buffering capacity of histidine facilitates endosomal membrane rupture and therefore enhances the transfection efficiency. The combination of high delivery efficiency in serum and low cytotoxicity suggests the denpol system as a promising new carrier for siRNA delivery. 10.1021/ja400986u
    A DNAzyme-gold nanoparticle probe for uranyl ion in living cells. Wu Peiwen,Hwang Kevin,Lan Tian,Lu Yi Journal of the American Chemical Society DNAzymes have shown great promise as a general platform for detecting metal ions, as many metal-specific DNAzymes can be obtained using in vitro selection. While DNAzyme-based metal sensors have found many applications in the extracellular environment, no intracellular application of DNAzyme sensors has yet been reported. Here, we demonstrate a novel type of metal ion sensor for intracellular metal ion detection. The probe consists of a 13 nm gold nanoparticle (AuNP) core functionalized with a shell consisting of a uranyl-specific 39E DNAzyme whose enzyme strand contains a thiol at the 3' end for conjugation to the AuNP, and whose substrate strand is modified with a Cy3 fluorophore at the 5' end and a molecular quencher at the 3' end. In the absence of uranyl, the fluorescence of the Cy3 is quenched by both AuNP and the molecular quencher. In the presence of uranyl, the DNAzyme cleaves the fluorophore-labeled substrate strand, resulting in release of the shorter product strand containing the Cy3 and increased fluorescence. We demonstrate that this DNAzyme-AuNP probe can readily enter cells and can serve as a metal ion sensor within a cellular environment, making it the first demonstration of DNAzymes as intracellular metal ion sensors. Such a method can be generally applied to the detection of other metal ions using other DNAzymes selected through in vitro selection. 10.1021/ja400150v
    Investigation of SSEA-4 binding protein in breast cancer cells. Hung Ting-Chun,Lin Chih-Wei,Hsu Tsui-Ling,Wu Chung-Yi,Wong Chi-Huey Journal of the American Chemical Society SSEA-4, a sialyl-glycolipid, has been commonly used as a pluripotent human embryonic stem cell marker, and its expression is correlated with the metastasis of some malignant tumors. However, there is no in-depth functional study related to the receptor and the role of this glycolipid. Here, we report the identification of an SSEA-4-binding protein in a breast cancer cell line, MCF-7. By using affinity capture and glycan microarray techniques, the intracellular FK-506 binding protein 4 (FKBP4) was identified to bind directly to SSEA-4. The biological significance of SSEA-4/FKBP4 interaction was investigated. 10.1021/ja312210c
    Directed differentiation of human embryonic stem cells toward chondrocytes. Oldershaw Rachel A,Baxter Melissa A,Lowe Emma T,Bates Nicola,Grady Lisa M,Soncin Francesca,Brison Daniel R,Hardingham Timothy E,Kimber Susan J Nature biotechnology We report a chemically defined, efficient, scalable and reproducible protocol for differentiation of human embryonic stem cells (hESCs) toward chondrocytes. HESCs are directed through intermediate developmental stages using substrates of known matrix proteins and chemically defined media supplemented with exogenous growth factors. Gene expression analysis suggests that the hESCs progress through primitive streak or mesendoderm to mesoderm, before differentiating into a chondrocytic culture comprising cell aggregates. At this final stage, 74% (HUES1 cells) and up to 95-97% (HUES7 and HUES8 cells) express the chondrogenic transcription factor SOX9. The cell aggregates also express cell surface CD44 and aggrecan and deposit a sulfated glycosaminoglycan and cartilage-specific collagen II matrix, but show very low or no expression of genes and proteins associated with nontarget cell types. Our protocol should facilitate studies of chondrocyte differentiation and of cell replacement therapies for cartilage repair. 10.1038/nbt.1683
    Clonal isolation of hESCs reveals heterogeneity within the pluripotent stem cell compartment. Stewart Morag H,Bossé Marc,Chadwick Kristin,Menendez Pablo,Bendall Sean C,Bhatia Mickie Nature methods Human embryonic stem cell (hESC) lines are known to be morphologically and phenotypically heterogeneous. The functional nature and relationship of cells residing within hESC cultures, however, has not been evaluated because isolation of single hESCs is limited to drug or manual selection. Here we provide a quantitative method using flow cytometry to isolate and clonally expand hESCs based on undifferentiated markers, alone or in combination with a fluorescent reporter. This method allowed for isolation of stage-specific embryonic antigen-3-positive (SSEA-3+) and SSEA-3- cells from hESC cultures. Although both SSEA-3+ and SSEA-3- cells could initiate pluripotent hESC cultures, we show that they possess distinct cell-cycle properties, clonogenic capacity and expression of ESC transcription factors. Our study provides formal evidence for heterogeneity among self-renewing pluripotent hESCs, illustrating that this isolation technique will be instrumental in further dissecting the biology of hESC lines. 10.1038/nmeth939
    Dendritic cell subsets digested: RNA sensing makes the difference! Buschow Sonja I,Figdor Carl G Immunity In this issue of Immunity, Luber et al. (2010) report a comprehensive quantitative proteome of in vivo mouse spleen dendritic cell (DC) subsets: a data set of encyclopedic value already revealing that DC subsets exploit different RNA sensors for virus recognition. 10.1016/j.immuni.2010.02.006
    Acute onset human atrial fibrillation is associated with local cardiac platelet activation and endothelial dysfunction. Akar Joseph G,Jeske Walter,Wilber David J Journal of the American College of Cardiology OBJECTIVES:The purpose of this study was to determine whether acute onset atrial fibrillation (AF), independent of other risk factors, predisposes to an early prothrombotic state. BACKGROUND:Several risk factors predispose to the hypercoagulable state in human AF, but whether acute onset AF alone is prothrombotic remains unclear. METHODS:Patients with paroxysmal AF (n = 22) underwent radiofrequency catheter ablation. All patients presented in sinus rhythm. Baseline blood samples were obtained simultaneously from the femoral vein (systemic sample) and the coronary sinus (local cardiac sample). The AF was induced by burst atrial pacing in 14 patients (AF group). A control group (n = 8) underwent atrial pacing at 120 beats/min. Blood samples were recollected after 15 min. Platelet P-selectin expression (CD62) was measured using flow cytometry. Markers of thrombin generation (thrombin antithrombin complex, prothrombin fragment 1.2), inflammation (C-reactive protein, interleukin-6), and nitric oxide were measured using enzyme-linked immunosorbent assays. RESULTS:Neither local nor systemic platelet activation changed in the control group. In the AF group, local cardiac platelet activation (percent P-selectin [+] platelets) increased significantly (2.2 +/- 0.6% to 2.8 +/- 1.0%, p = 0.007); however, systemic platelet activation did not change. The AF group had increased local thrombin generation (thrombin antithrombin complex: 8.5 +/- 7.6 ng/ml to 33.2 +/- 17.4 ng/ml, p = 0.003; prothrombin fragment 1.2: 95.6 +/- 45.6 micromol/l to 243.8 +/- 120.1 micromol/l, p = 0.003), decreased nitric oxide production (25.2 +/- 10.8 micromol/l to 22.3 +/- 10.0 micromol/l, p < 0.02), and no change in inflammatory markers. CONCLUSIONS:Human AF causes local cardiac platelet activation within minutes of onset. The results demonstrate how AF alone, independent of other risk factors, may contribute to the hypercoagulable state. 10.1016/j.jacc.2007.11.083
    Node-negative breast cancer: prognostic subgroups defined by tumor size and flow cytometry. O'Reilly S M,Camplejohn R S,Barnes D M,Millis R R,Rubens R D,Richards M A Journal of clinical oncology : official journal of the American Society of Clinical Oncology Adjuvant systemic therapy for women with node-negative breast cancer is most easily justified for those patients at highest risk of relapse. We have examined the impact of tumor size, histologic grade, estrogen receptor (ER) status, tumor ploidy, and S-phase fraction (SPF) on relapse-free survival (RFS) for 169 patients with node-negative breast cancer in order to identify groups of patients at high and low risk of relapse. Patients with small tumors (less than or equal to 1.0 cm) had a significantly better RFS than those with larger tumors (P = .005), with 96% remaining relapse-free at 5 years. Patients with tumors less than or equal to 1.0 cm were thus excluded from analysis when attempting to define a group with a poor prognosis. Within the group of patients with tumors greater than 1.0 cm, tumor ploidy (P = .63), ER status (P = .3), or progesterone receptor (PgR) status (P = .24) did not predict for RFS. Patients with grade 1 or 2 infiltrating ductal tumors had a significantly better prognosis than those with grade 3 tumors (P = .04). The prognostic factor that gave the widest separation between subgroups, however, was SPF. Patients whose tumors were greater than 1.0 cm with an SPF less than or equal to 10% had a 5-year RFS of 78% compared with a 5-year RFS of 52% for those with an SPF greater than 10% (P = .006). We have combined tumor size and SPF to identify three prognostic groups: (1) tumor less than or equal to 1.0 cm, 5-year RFS 96%; (2) tumor greater than 1.0 cm plus SPF less than or equal to 10%, 5-year RFS 78%; 3) tumor greater than 1.0 cm plus SPF greater than 10%, 5-year RFS 52%. These prognostic groupings may help identify patients most suitable for adjuvant therapy. 10.1200/JCO.1990.8.12.2040
    Tropheryma whipplei Increases Expression of Human Leukocyte Antigen-G on Monocytes to Reduce Tumor Necrosis Factor and Promote Bacterial Replication. Ben Azzouz Eya,Boumaza Asma,Mezouar Soraya,Bardou Matthieu,Carlini Federico,Picard Christophe,Raoult Didier,Mège Jean-Louis,Desnues Benoit Gastroenterology BACKGROUND & AIMS:Infection with Tropheryma whipplei has a range of effects-some patients can be chronic carriers without developing any symptoms, whereas others can develop systemic Whipple disease, characterized by a lack a protective inflammatory immune response. Alterations in HLA-G function have been associated with several diseases. We investigated the role of HLA-G during T whipplei infection. METHODS:Sera, total RNA, and genomic DNA were collected from peripheral blood from 22 patients with classic Whipple's disease, 19 patients with localized T whipplei infections, and 21 asymptomatic carriers. Levels of soluble HLA-G in sera were measured by enzyme-linked immuosorbent assay, and expressions of HLA-G and its isoforms were monitored by real-time polymerase chain reaction. HLA-G alleles were identified and compared with a population of voluntary bone marrow donors. Additionally, monocytes from healthy subjects were stimulated with T whipplei, and HLA-G expression was monitored by real-time polymerase chain reaction and flow cytometry. Bacterial replication was assessed by polymerase chain reaction in the presence of HLA-G or inhibitor of tumor necrosis factor (TNF) (etanercept). RESULTS:HLA-G mRNAs and levels of soluble HLA-G were significantly increased in sera from patients with chronic T whipplei infection compared with sera from asymptomatic carriers and control individuals. No specific HLA-G haplotypes were associated with disease or T whipplei infection. However, T whipplei infection of monocytes induced expression of HLA-G, which was associated with reduced secretion of TNF compared with noninfected monocytes. A neutralizing antibody against HLA-G increased TNF secretion by monocytes in response to T whipplei, and a TNF inhibitor promoted bacteria replication. CONCLUSIONS:Levels of HLA-G are increased in sera from patients with T whipplei tissue infections, associated with reduced production of TNF by monocytes. This might promote bacteria colonization in patients. 10.1053/j.gastro.2018.07.034
    Quantitative proteomics reveals subset-specific viral recognition in dendritic cells. Luber Christian A,Cox Jürgen,Lauterbach Henning,Fancke Ben,Selbach Matthias,Tschopp Jurg,Akira Shizuo,Wiegand Marian,Hochrein Hubertus,O'Keeffe Meredith,Mann Matthias Immunity Dendritic cell (DC) populations consist of multiple subsets that are essential orchestrators of the immune system. Technological limitations have so far prevented systems-wide accurate proteome comparison of rare cell populations in vivo. Here, we used high-resolution mass spectrometry-based proteomics, combined with label-free quantitation algorithms, to determine the proteome of mouse splenic conventional and plasmacytoid DC subsets to a depth of 5,780 and 6,664 proteins, respectively. We found mutually exclusive expression of pattern recognition pathways not previously known to be different among conventional DC subsets. Our experiments assigned key viral recognition functions to be exclusively expressed in CD4(+) and double-negative DCs. The CD8alpha(+) DCs largely lack the receptors required to sense certain viruses in the cytoplasm. By avoiding activation via cytoplasmic receptors, including retinoic acid-inducible gene I, CD8alpha(+) DCs likely gain a window of opportunity to process and present viral antigens before activation-induced shutdown of antigen presentation pathways occurs. 10.1016/j.immuni.2010.01.013
    Salmonella Infection Drives Promiscuous B Cell Activation Followed by Extrafollicular Affinity Maturation. Di Niro Roberto,Lee Seung-Joo,Vander Heiden Jason A,Elsner Rebecca A,Trivedi Nikita,Bannock Jason M,Gupta Namita T,Kleinstein Steven H,Vigneault Francois,Gilbert Tamara J,Meffre Eric,McSorley Stephen J,Shlomchik Mark J Immunity The B cell response to Salmonella typhimurium (STm) occurs massively at extrafollicular sites, without notable germinal centers (GCs). Little is known in terms of its specificity. To expand the knowledge of antigen targets, we screened plasmablast (PB)-derived monoclonal antibodies (mAbs) for Salmonella specificity, using ELISA, flow cytometry, and antigen microarray. Only a small fraction (0.5%-2%) of the response appeared to be Salmonella-specific. Yet, infection of mice with limited B cell receptor (BCR) repertoires impaired the response, suggesting that BCR specificity was important. We showed, using laser microdissection, that somatic hypermutation (SHM) occurred efficiently at extrafollicular sites leading to affinity maturation that in turn led to detectable STm Ag-binding. These results suggest a revised vision of how clonal selection and affinity maturation operate in response to Salmonella. Clonal selection initially is promiscuous, activating cells with virtually undetectable affinity, yet SHM and selection occur during the extrafollicular response yielding higher affinity, detectable antibodies. 10.1016/j.immuni.2015.06.013
    Case records of the Massachusetts General Hospital. Case 27-2013. A 6.5-month-old boy with fever, rash, and cytopenias. Iyengar Shuba R,Ebb David H,Yuan Qian,Shailam Randheer,Bhan Atul K The New England journal of medicine 10.1056/NEJMcpc1209277
    Enteric defensins are essential regulators of intestinal microbial ecology. Salzman Nita H,Hung Kuiechun,Haribhai Dipica,Chu Hiutung,Karlsson-Sjöberg Jenny,Amir Elad,Teggatz Paul,Barman Melissa,Hayward Michael,Eastwood Daniel,Stoel Maaike,Zhou Yanjiao,Sodergren Erica,Weinstock George M,Bevins Charles L,Williams Calvin B,Bos Nicolaas A Nature immunology Antimicrobial peptides are important effectors of innate immunity throughout the plant and animal kingdoms. In the mammalian small intestine, Paneth cell alpha-defensins are antimicrobial peptides that contribute to host defense against enteric pathogens. To determine if alpha-defensins also govern intestinal microbial ecology, we analyzed the intestinal microbiota of mice expressing a human alpha-defensin gene (DEFA5) and in mice lacking an enzyme required for the processing of mouse alpha-defensins. In these complementary models, we detected significant alpha-defensin-dependent changes in microbiota composition, but not in total bacterial numbers. Furthermore, DEFA5-expressing mice had striking losses of segmented filamentous bacteria and fewer interleukin 17 (IL-17)-producing lamina propria T cells. Our data ascribe a new homeostatic role to alpha-defensins in regulating the makeup of the commensal microbiota. 10.1038/ni.1825
    Different routes of bacterial infection induce long-lived TH1 memory cells and short-lived TH17 cells. Pepper Marion,Linehan Jonathan L,Pagán Antonio J,Zell Traci,Dileepan Thamotharampillai,Cleary P Patrick,Jenkins Marc K Nature immunology We used a sensitive method based on tetramers of peptide and major histocompatibility complex II (pMHCII) to determine whether CD4(+) memory T cells resemble the T helper type 1 (T(H)1) and interleukin 17 (IL-17)-producing T helper (T(H)17) subsets described in vitro. Intravenous or intranasal infection with Listeria monocytogenes induced pMHCII-specific CD4(+) naive T cells to proliferate and produce effector cells, about 10% of which resembled T(H)1 or T(H)17 cells, respectively. T(H)1 cells were also present among the memory cells that survived 3 months after infection, whereas T(H)17 cells disappeared. The short lifespan of T(H)17 cells was associated with small amounts of the antiapoptotic protein Bcl-2, the IL-15 receptor and the receptor CD27, and little homeostatic proliferation. These results suggest that T(H)1 cells induced by intravenous infection are more efficient at entering the memory pool than are T(H)17 cells induced by intranasal infection. 10.1038/ni.1826
    HLA-C Level Is Regulated by a Polymorphic Oct1 Binding Site in the HLA-C Promoter Region. Vince Nicolas,Li Hongchuan,Ramsuran Veron,Naranbhai Vivek,Duh Fuh-Mei,Fairfax Benjamin P,Saleh Bahara,Knight Julian C,Anderson Stephen K,Carrington Mary American journal of human genetics Differential HLA-C levels influence several human diseases, but the mechanisms responsible are incompletely characterized. Using a validated prediction algorithm, we imputed HLA-C cell surface levels in 228 individuals from the 1000 Genomes dataset. We tested 68,726 SNPs within the MHC for association with HLA-C level. The HLA-C promoter region variant, rs2395471, 800 bp upstream of the transcription start site, gave the most significant association with HLA-C levels (p = 4.2 × 10). This imputed expression quantitative trait locus, termed impeQTL, was also shown to associate with HLA-C expression in a genome-wide association study of 273 donors in which HLA-C mRNA expression levels were determined by quantitative PCR (qPCR) (p = 1.8 × 10) and in two cohorts where HLA-C cell surface levels were determined directly by flow cytometry (n = 369 combined, p < 10). rs2395471 is located in an Oct1 transcription factor consensus binding site motif where the A allele is predicted to have higher affinity for Oct1 than the G allele. Mobility shift electrophoresis demonstrated that Oct1 binds to both alleles in vitro, but decreased HLA-C promoter activity was observed in a luciferase reporter assay for rs2395471_G relative to rs2395471_A on a fixed promoter background. The rs2395471 variant accounts for up to 36% of the explained variation of HLA-C level. These data strengthen our understanding of HLA-C transcriptional regulation and provide a basis for understanding the potential consequences of manipulating HLA-C levels therapeutically. 10.1016/j.ajhg.2016.09.023
    Graft-versus-host disease is enhanced by extracellular ATP activating P2X7R. Wilhelm Konrad,Ganesan Jayanthi,Müller Tobias,Dürr Christoph,Grimm Melanie,Beilhack Andreas,Krempl Christine D,Sorichter Stephan,Gerlach Ulrike V,Jüttner Eva,Zerweck Alf,Gärtner Frank,Pellegatti Patrizia,Di Virgilio Francesco,Ferrari Davide,Kambham Neeraja,Fisch Paul,Finke Jürgen,Idzko Marco,Zeiser Robert Nature medicine Danger signals released upon cell damage can cause excessive immune-mediated tissue destruction such as that found in acute graft-versus-host disease (GVHD), allograft rejection and systemic inflammatory response syndrome. Given that ATP is found in small concentrations in the extracellular space under physiological conditions, and its receptor P2X(7)R is expressed on several immune cell types, ATP could function as a danger signal when released from dying cells. We observed increased ATP concentrations in the peritoneal fluid after total body irradiation, and during the development of GVHD in mice and in humans. Stimulation of antigen-presenting cells (APCs) with ATP led to increased expression of CD80 and CD86 in vitro and in vivo and actuated a cascade of proinflammatory events, including signal transducer and activator of transcription-1 (STAT1) phosphorylation, interferon-γ (IFN-γ) production and donor T cell expansion, whereas regulatory T cell numbers were reduced. P2X(7)R expression increased when GVHD evolved, rendering APCs more responsive to the detrimental effects of ATP, thereby providing positive feedback signals. ATP neutralization, early P2X(7)R blockade or genetic deficiency of P2X(7)R during GVHD development improved survival without immune paralysis. These data have major implications for transplantation medicine, as pharmacological interference with danger signals that act via P2X(7)R could lead to the development of tolerance without the need for intensive immunosuppression. 10.1038/nm.2242
    Conversion of vascular endothelial cells into multipotent stem-like cells. Medici Damian,Shore Eileen M,Lounev Vitali Y,Kaplan Frederick S,Kalluri Raghu,Olsen Bjorn R Nature medicine Mesenchymal stem cells can give rise to several cell types, but varying results depending on isolation methods and tissue source have led to controversies about their usefulness in clinical medicine. Here we show that vascular endothelial cells can transform into multipotent stem-like cells by an activin-like kinase-2 (ALK2) receptor-dependent mechanism. In lesions from individuals with fibrodysplasia ossificans progressiva (FOP), a disease in which heterotopic ossification occurs as a result of activating ALK2 mutations, or from transgenic mice expressing constitutively active ALK2, chondrocytes and osteoblasts expressed endothelial markers. Lineage tracing of heterotopic ossification in mice using a Tie2-Cre construct also suggested an endothelial origin of these cell types. Expression of constitutively active ALK2 in endothelial cells caused endothelial-to-mesenchymal transition and acquisition of a stem cell-like phenotype. Similar results were obtained by treatment of untransfected endothelial cells with the ligands transforming growth factor-β2 (TGF-β2) or bone morphogenetic protein-4 (BMP4) in an ALK2-dependent manner. These stem-like cells could be triggered to differentiate into osteoblasts, chondrocytes or adipocytes. We suggest that conversion of endothelial cells to stem-like cells may provide a new approach to tissue engineering. 10.1038/nm.2252
    T helper type 1 memory cells disseminate postoperative ileus over the entire intestinal tract. Engel Daniel R,Koscielny Arne,Wehner Sven,Maurer Juliane,Schiwon Marzena,Franken Lars,Schumak Beatrix,Limmer Andreas,Sparwasser Tim,Hirner Andreas,Knolle Percy A,Kalff Jörg C,Kurts Christian Nature medicine Localized abdominal surgery can lead to disruption of motility in the entire gastrointestinal tract (postoperative ileus). Intestinal macrophages produce mediators that paralyze myocytes, but it is unclear how the macrophages are activated, especially those in unmanipulated intestinal areas. Here we show that intestinal surgery activates intestinal CD103(+)CD11b(+) dendritic cells (DCs) to produce interleukin-12 (IL-12). This promotes interferon-γ (IFN-γ) secretion by CCR9(+) memory T helper type 1 (T(H)1) cells which activates the macrophages. IL-12 also caused some T(H)1 cells to migrate from surgically manipulated sites through the bloodstream to unmanipulated intestinal areas where they induced ileus. Preventing T cell migration with the drug FTY720 or inhibition of IL-12, T-bet (T(H)1-specific T box transcription factor) or IFN-γ prevented postoperative ileus. CCR9(+) T(H)1 memory cells were detected in the venous blood of subjects 1 h after abdominal surgery. These findings indicate that postoperative ileus is a T(H)1 immune-mediated disease and identify potential targets for disease monitoring and therapy. 10.1038/nm.2255
    Deficiency of GATA3-Positive Macrophages Improves Cardiac Function Following Myocardial Infarction or Pressure Overload Hypertrophy. Yang Mingjie,Song Lei,Wang Lai,Yukht Ada,Ruther Haley,Li Fuqiang,Qin Minghui,Ghiasi Homayon,Sharifi Behrooz G,Shah Prediman K Journal of the American College of Cardiology BACKGROUND:Macrophages are highly plastic cells that play an important role in the pathogenesis of cardiovascular disease. OBJECTIVES:This study investigated the role of GATA3-positive macrophages in modulating cardiac function after myocardial infarction (MI) or in response to pressure overload hypertrophy. METHODS:Myeloid-specific GATA3-deficient (mGATA3KO) mice were generated, MI or pressure overload was induced, and cardiac function was determined by echocardiography. GATA3-sufficient Cre mice were used as a control. Immunohistochemical staining, flow cytometry, MILLIPLEX Mouse Cytokine/Chemokine Assay, cultured macrophages, quantitative real-time polymerase chain reaction, and western blot were used to determine the role of GATA3 in macrophages. RESULTS:GATA3-positive macrophages rapidly accumulated in the infarcted region of the myocardium after acute MI. Deficiency of GATA3-positive macrophages led to a significant improvement of cardiac function in response to acute MI or pressure overload hypertrophy compared with the control mice. This improvement was associated with the presence of a large number of proinflammatory Ly6C monocytes/macrophages and fewer reparative Ly6C macrophages in the myocardium of mGATA3KO mice compared with control mice. Analysis of serum proteins from the 2 mouse genotypes revealed no major changes in the profile of serum growth factors and cytokines between the 2 mice genotypes before and after MI. GATA3 was found to be specifically and transiently induced by interleukin 4 in cultured macrophages through activity of the proximal promoter, whereas the distal promoter remained silent. In addition, the absence of GATA3 in macrophages markedly attenuated arginase-1 expression in cultured macrophages. CONCLUSIONS:We demonstrated that the presence of GATA3-positive macrophages adversely affects remodeling of the myocardium in response to ischemia or pressure overload, whereas the absence of these macrophages led to a significant improvement in cardiac function. Targeting of signaling pathways that lead to the expression of GATA3 in macrophages may have favorable cardiac outcomes. 10.1016/j.jacc.2018.05.061
    Dysregulation of allergic airway inflammation in the absence of microbial colonization. Herbst Tina,Sichelstiel Anke,Schär Corinne,Yadava Koshika,Bürki Kurt,Cahenzli Julia,McCoy Kathy,Marsland Benjamin J,Harris Nicola L American journal of respiratory and critical care medicine RATIONALE:The incidence of allergic disorders is increasing in developed countries and has been associated with reduced exposure to microbes and alterations in the commensal bacterial flora. OBJECTIVES:To ascertain the relevance of commensal bacteria on the development of an allergic response, we used a model of allergic airway inflammation in germ-free (GF) mice that lack any exposure to pathogenic or nonpathogenic microorganisms. METHODS:Allergic airway inflammation was induced in GF, specific pathogen-free (SPF), or recolonized mice by sensitization and challenge with ovalbumin. The resulting cellular infiltrate and cytokine production were measured. MEASUREMENTS AND MAIN RESULTS:Our results show that the total number of infiltrating lymphocytes and eosinophils were elevated in the airways of allergic GF mice compared with control SPF mice, and that this increase could be reversed by recolonization of GF mice with the complex commensal flora of SPF mice. Exaggerated airway eosinophilia correlated with increased local production of Th2-associated cytokines, elevated IgE production, and an altered number and phenotype of conventional dendritic cells. Regulatory T-cell populations and regulatory cytokine levels were unaltered, but GF mice exhibited an increased number of basophils and decreased numbers of alveolar macrophages and plasmacytoid dendritic cells. CONCLUSIONS:These data demonstrate that the presence of commensal bacteria is critical for ensuring normal cellular maturation, recruitment, and control of allergic airway inflammation. 10.1164/rccm.201010-1574OC
    Reversible and adaptive resistance to BRAF(V600E) inhibition in melanoma. Sun Chong,Wang Liqin,Huang Sidong,Heynen Guus J J E,Prahallad Anirudh,Robert Caroline,Haanen John,Blank Christian,Wesseling Jelle,Willems Stefan M,Zecchin Davide,Hobor Sebastijan,Bajpe Prashanth K,Lieftink Cor,Mateus Christina,Vagner Stephan,Grernrum Wipawadee,Hofland Ingrid,Schlicker Andreas,Wessels Lodewyk F A,Beijersbergen Roderick L,Bardelli Alberto,Di Nicolantonio Federica,Eggermont Alexander M M,Bernards Rene Nature Treatment of BRAF(V600E) mutant melanoma by small molecule drugs that target the BRAF or MEK kinases can be effective, but resistance develops invariably. In contrast, colon cancers that harbour the same BRAF(V600E) mutation are intrinsically resistant to BRAF inhibitors, due to feedback activation of the epidermal growth factor receptor (EGFR). Here we show that 6 out of 16 melanoma tumours analysed acquired EGFR expression after the development of resistance to BRAF or MEK inhibitors. Using a chromatin-regulator-focused short hairpin RNA (shRNA) library, we find that suppression of sex determining region Y-box 10 (SOX10) in melanoma causes activation of TGF-β signalling, thus leading to upregulation of EGFR and platelet-derived growth factor receptor-β (PDGFRB), which confer resistance to BRAF and MEK inhibitors. Expression of EGFR in melanoma or treatment with TGF-β results in a slow-growth phenotype with cells displaying hallmarks of oncogene-induced senescence. However, EGFR expression or exposure to TGF-β becomes beneficial for proliferation in the presence of BRAF or MEK inhibitors. In a heterogeneous population of melanoma cells having varying levels of SOX10 suppression, cells with low SOX10 and consequently high EGFR expression are rapidly enriched in the presence of drug, but this is reversed when the drug treatment is discontinued. We find evidence for SOX10 loss and/or activation of TGF-β signalling in 4 of the 6 EGFR-positive drug-resistant melanoma patient samples. Our findings provide a rationale for why some BRAF or MEK inhibitor-resistant melanoma patients may regain sensitivity to these drugs after a 'drug holiday' and identify patients with EGFR-positive melanoma as a group that may benefit from re-treatment after a drug holiday. 10.1038/nature13121
    Low-dose interleukin 2 in patients with type 1 diabetes: a phase 1/2 randomised, double-blind, placebo-controlled trial. Hartemann Agnès,Bensimon Gilbert,Payan Christine A,Jacqueminet Sophie,Bourron Olivier,Nicolas Nathalie,Fonfrede Michèle,Rosenzwajg Michelle,Bernard Claude,Klatzmann David The lancet. Diabetes & endocrinology BACKGROUND:An improper balance of regulatory/effector T (Treg/Teff) cells is central to the development of autoimmune diseases, including type 1 diabetes. We previously showed that low-dose interleukin 2 (IL2) induced Treg cell expansion and activation and clinical improvement in patients with hepatitis-C-virus-induced vasculitis. We aimed to establish which low doses of IL2 would be safe and induce Treg cells in patients with type 1 diabetes, considering that: (1) type 1 diabetes might be linked to alteration of the IL2/IL2R activation pathway; (2) activation of pathogenic Teff cells by IL2 could exacerbate disease; and (3) the safety of low-dose IL2 is not known in type 1 diabetes. METHODS:This was a single-centre phase 1/2 study. 24 adult patients (18-55 years) with established insulin-dependent type 1 diabetes and at least one diabetes-related autoantibody were enrolled and randomly assigned (in a 1:1:1:1 ratio, by computer-generated randomisation list, with block size four) to placebo or IL2 at 0.33 MIU/day, 1 MIU/day, or 3 MIU/day for a 5-day course and were followed up for 60 days. All investigators and participants were masked to assignment. The primary outcome was change in Treg cells, measured by flow cytometry, and expressed as a percentage of CD4+ T cells, from day 1 to day 60. This trial is registered with ClinicalTrials.gov, number NCT01353833. FINDINGS:Six patients were assigned to each group between June 1, 2011, and Feb 3, 2012. IL2 was well tolerated at all doses, with no serious adverse events. However, there was a dose-response association for non-serious adverse events during the treatment phase (days 1-6); one patient in the placebo group, three patients in the 0.33 MIU group, five patients in the 1 MIU group, and six patients in the 3 MIU group had non-serious adverse events. The most common adverse events in the treatment phase were injection-site reaction (no patients with placebo vs three patients with 0.33 MIU and 1 MIU vs two patients with 3 MIU) and influenza-like syndrome (no patients with placebo vs one patient with 0.33 MIU and 1 MIU vs four patients with 3 MIU). After the treatment phase, adverse events did not differ between groups. IL2 did not induce deleterious changes in glucose-metabolism variables. IL2 induced a dose-dependent increase in the proportion of Treg cells, significant at all doses compared with placebo (placebo mean increase 0.5% [SD 0.4]; 0.33 MIU 2.8% [1.2], p=0.0039; 1 MIU 3.9% [1.8], p=0.0039; 3 MIU 4.8% [1.9] p=0.0039). INTERPRETATION:We have defined a well-tolerated and immunologically effective dose range of IL2 for application to type 1 diabetes therapy and prevention, which could be relevant to other disorders in which a Treg cell increase would be desirable. 10.1016/S2213-8587(13)70113-X
    GM-CSF in the lung protects against lethal influenza infection. Huang Fang-Fang,Barnes Peter F,Feng Yan,Donis Ruben,Chroneos Zissis C,Idell Steven,Allen Timothy,Perez Daniel R,Whitsett Jeffrey A,Dunussi-Joannopoulos Kyri,Shams Homayoun American journal of respiratory and critical care medicine RATIONALE:Alveolar macrophages contribute to host defenses against influenza in animal models. Enhancing alveolar macrophage function may contribute to protection against influenza. OBJECTIVES:To determine if increased expression of granulocyte/macrophage colony-stimulating factor (GM-CSF) in the lung increases resistance to influenza. METHODS:Wild-type mice and transgenic mice that expressed GM-CSF in the lung were infected with influenza virus, and lung pathology, weight loss, and mortality were measured. We also administered GM-CSF to the lungs of wild-type mice that were infected with influenza virus. MEASUREMENTS AND MAIN RESULTS:Wild-type mice all died after infection with different strains of influenza virus, but all transgenic mice expressing GM-CSF in the lungs survived. The latter also had greatly reduced weight loss and lung injury, and showed histologic evidence of a rapid host inflammatory response that controlled infection. The resistance of transgenic mice to influenza was abrogated by elimination of alveolar phagocytes, but not by depletion of T cells, B cells, or neutrophils. Transgenic mice had far more alveolar macrophages than did wild-type mice, and they were more resistant to influenza-induced apoptosis. Delivery of intranasal GM-CSF to wild-type mice also conferred resistance to influenza. CONCLUSIONS:GM-CSF confers resistance to influenza by enhancing innate immune mechanisms that depend on alveolar macrophages. Pulmonary delivery of this cytokine has the potential to reduce the morbidity and mortality due to influenza virus. 10.1164/rccm.201012-2036OC
    Clearance of Somatic Mutations at Remission and the Risk of Relapse in Acute Myeloid Leukemia. Morita Kiyomi,Kantarjian Hagop M,Wang Feng,Yan Yuanqing,Bueso-Ramos Carlos,Sasaki Koji,Issa Ghayas C,Wang Sa,Jorgensen Jeffrey,Song Xingzhi,Zhang Jianhua,Tippen Samantha,Thornton Rebecca,Coyle Marcus,Little Latasha,Gumbs Curtis,Pemmaraju Naveen,Daver Naval,DiNardo Courtney D,Konopleva Marina,Andreeff Michael,Ravandi Farhad,Cortes Jorge E,Kadia Tapan,Jabbour Elias,Garcia-Manero Guillermo,Patel Keyur P,Futreal P Andrew,Takahashi Koichi Journal of clinical oncology : official journal of the American Society of Clinical Oncology Purpose The aim of the current study was to determine whether the degree of mutation clearance at remission predicts the risk of relapse in patients with acute myeloid leukemia (AML). Patients and Methods One hundred thirty-one previously untreated patients with AML who received intensive induction chemotherapy and attained morphologic complete remission (CR) at day 30 were studied. Pretreatment and CR bone marrow were analyzed using targeted capture DNA sequencing. We analyzed the association between mutation clearance (MC) on the basis of variant allele frequency (VAF) at CR (MC2.5: if the VAF of residual mutations was < 2.5%; MC1.0: if the VAF was < 1%; and complete MC [CMC]: if no detectable residual mutations) and event-free survival, overall survival (OS), and cumulative incidence of relapse (CIR). Results MC1.0 and CMC were associated with significantly better OS (2-year OS: 75% v 61% in MC1.0 v non-MC1.0; P = .0465; 2-year OS: 77% v 60% in CMC v non-CMC; P = .0303) and lower CIR (2-year CIR: 26% v 46% in MC1.0 v non-MC 1.0; P = .0349; 2 year-CIR: 24% v 46% in CMC v non-CMC; P = .03), whereas there was no significant difference in any of the above outcomes by MC2.5. Multivariable analysis adjusting for age, cytogenetic risk, allogeneic stem-cell transplantation, and flow cytometry-based minimal residual disease revealed that patients with CMC had significantly better event-free survival (hazard ratio [HR], 0.43; P = .0083), OS (HR, 0.47; P = .04), and CIR (HR, 0.27; P < .001) than did patients without CMC. These prognostic associations were stronger when preleukemic mutations, such as DNMT3A, TET2, and ASXL1, were removed from the analysis. Conclusion Clearance of somatic mutation at CR, particularly in nonpreleukemic genes, was associated with significantly better survival and less risk of relapse. Somatic mutations in nonpreleukemic genes may function as a molecular minimal residual disease marker in AML. 10.1200/JCO.2017.77.6757
    Signature of long-lived memory CD8 T cells in acute SARS-CoV-2 infection. Nature Immunological memory is a hallmark of adaptive immunity and facilitates an accelerated and enhanced immune response upon re-infection with the same pathogen. Since the outbreak of the ongoing COVID-19 pandemic, a key question has focused on which SARS-CoV-2-specific T cells stimulated during acute infection give rise to long-lived memory T cells. Here, using spectral flow cytometry combined with cellular indexing of transcriptomes and T cell receptor sequencing, we longitudinally characterized individual SARS-CoV-2-specific CD8 T cells of patients with COVID-19 from acute infection to 1 year into recovery and found a distinct signature identifying long-lived memory CD8 T cells. SARS-CoV-2-specific memory CD8 T cells persisting 1 year after acute infection express CD45RA, IL-7 receptor-α and T cell factor 1, but they maintain low expression of CCR7, thus resembling CD45RA effector memory T cells. Tracking individual clones of SARS-CoV-2-specific CD8 T cells, we reveal that an interferon signature marks clones that give rise to long-lived cells, whereas prolonged proliferation and mechanistic target of rapamycin signalling are associated with clonal disappearance from the blood. Collectively, we describe a transcriptional signature that marks long-lived, circulating human memory CD8 T cells following an acute viral infection. 10.1038/s41586-021-04280-x
    Attenuated P2X7 pore function as a risk factor for virus-induced loss of asthma control. Denlinger Loren C,Shi Lei,Guadarrama Arturo,Schell Kathy,Green Dawn,Morrin Alison,Hogan Kirk,Sorkness Ronald L,Busse William W,Gern James E American journal of respiratory and critical care medicine RATIONALE:Upper respiratory tract infection is a guideline accepted risk domain for the loss of asthma control. The ionotrophic nucleotide receptor P2X(7) regulates compartmentalized acute inflammation and the immune response to airway pathogens. OBJECTIVES:We hypothesized that variability in P2X(7) function contributes to neutrophilic airway inflammation during a cold and thereby is linked to acute asthma. METHODS:Research volunteers with asthma were enrolled at the onset of a naturally occurring cold and monitored through convalescence, assessing symptoms, lung function, and airway inflammation. P2X(7) pore activity in whole blood samples was measured using a genomically validated flow cytometric assay. MEASUREMENTS AND MAIN RESULTS:Thirty-five participants with mild to moderate allergic asthma were enrolled and 31 completed all visits. P2X(7) pore function correlated with the change in nasal lavage neutrophil counts during the cold (R(s) = 0.514, P = 0.004) and was inversely related to the change in asthma symptoms (R(s) = -0.486, P = 0.009). The change in peak expiratory flow recordings, precold use of inhaled corticosteroids, and P2X(7) pore function were multivariate predictors of asthma symptoms (P = 0.001, < 0.001 and = 0.003 respectively). Attenuated P2X(7) activity was associated with the risk of losing asthma control (crude odds ratio, 11.0; 95% confidence interval, 1.1-106.4) even after adjustment for inhaled corticosteroids and rhinovirus (odds ratio, 15.0). CONCLUSIONS:A whole blood P2X(7) pore assay robustly identifies participants with loss-of-function genotypes. Using this assay as an epidemiologic tool, attenuated P2X(7) pore activity may be a novel biomarker of virus-induced loss of asthma control. 10.1164/rccm.200802-293OC
    Rab27a and Rab27b control different steps of the exosome secretion pathway. Ostrowski Matias,Carmo Nuno B,Krumeich Sophie,Fanget Isabelle,Raposo Graça,Savina Ariel,Moita Catarina F,Schauer Kristine,Hume Alistair N,Freitas Rui P,Goud Bruno,Benaroch Philippe,Hacohen Nir,Fukuda Mitsunori,Desnos Claire,Seabra Miguel C,Darchen François,Amigorena Sebastian,Moita Luis F,Thery Clotilde Nature cell biology Exosomes are secreted membrane vesicles that share structural and biochemical characteristics with intraluminal vesicles of multivesicular endosomes (MVEs). Exosomes could be involved in intercellular communication and in the pathogenesis of infectious and degenerative diseases. The molecular mechanisms of exosome biogenesis and secretion are, however, poorly understood. Using an RNA interference (RNAi) screen, we identified five Rab GTPases that promote exosome secretion in HeLa cells. Among these, Rab27a and Rab27b were found to function in MVE docking at the plasma membrane. The size of MVEs was strongly increased by Rab27a silencing, whereas MVEs were redistributed towards the perinuclear region upon Rab27b silencing. Thus, the two Rab27 isoforms have different roles in the exosomal pathway. In addition, silencing two known Rab27 effectors, Slp4 (also known as SYTL4, synaptotagmin-like 4) and Slac2b (also known as EXPH5, exophilin 5), inhibited exosome secretion and phenocopied silencing of Rab27a and Rab27b, respectively. Our results therefore strengthen the link between MVEs and exosomes, and introduce ways of manipulating exosome secretion in vivo. 10.1038/ncb2000
    Allergen-induced Increases in Sputum Levels of Group 2 Innate Lymphoid Cells in Subjects with Asthma. Chen Ruchong,Smith Steven G,Salter Brittany,El-Gammal Amani,Oliveria John Paul,Obminski Caitlin,Watson Rick,O'Byrne Paul M,Gauvreau Gail M,Sehmi Roma American journal of respiratory and critical care medicine RATIONALE:Group 2 innate lymphoid cells (ILC2), a major source of type 2 cytokines, initiate eosinophilic inflammatory responses in murine models of asthma. OBJECTIVES:To investigate the role of ILC2 in allergen-induced airway eosinophilic responses in subjects with atopy and asthma. METHODS:Using a diluent-controlled allergen challenge crossover study, where all subjects (n = 10) developed allergen-induced early and late responses, airway eosinophilia, and increased methacholine airway responsiveness, bone marrow, blood, and sputum samples were collected before and after inhalation challenge. MEASUREMENTS AND MAIN RESULTS:ILC2 (linFcεRICD45CD127ST2) and CD4T lymphocytes were enumerated by flow cytometry, as well as intracellular IL-5 and IL-13 expression. Steroid sensitivity of ILC2 and CD4 T cells was investigated in vitro. A significant increase in total, IL-5, IL-13, and CRTH2 ILC2 was found in sputum, 24 hours after allergen, coincident with a significant decrease in blood ILC2. Total, IL-5, and IL-13, but not CRTH2, CD4 T cells significantly increased at 24 and 48 hours after allergen in sputum. In blood and bone marrow, only CD4 cells demonstrated increased activation after allergen. Airway eosinophilia correlated with IL-5 ILC2 at all time points and allergen-induced changes in IL-5 CD4 cells at 48 hours after allergen. Dexamethasone significantly attenuated IL-2- and IL-33-stimulated IL-5 and IL-13 production by both cell types. CONCLUSIONS:Innate and adaptive immune cells are increased in the airways associated with allergic asthmatic responses. Total and type 2 cytokine-positive ILC2 are increased only within the airways, whereas CD4 T lymphocytes demonstrated local and systemic increases. Steroid sensitivity of both cells may explain effectiveness of this therapy in those with mild asthma. 10.1164/rccm.201612-2427OC
    Diffuse osteosclerosis-associated acute myeloid leukemia. Ward David E,Fondaw Megan B,Shroff Sonalee K,Reddy Vijay S,Khaled Yasser A Journal of clinical oncology : official journal of the American Society of Clinical Oncology 10.1200/JCO.2011.37.4983
    The effect of 1.5 T cardiac magnetic resonance on human circulating leucocytes. Critchley William R,Reid Anna,Morris Julie,Naish Josephine H,Stone John P,Ball Alexandra L,Major Triin,Clark David,Waldron Nick,Fortune Christien,Lagan Jakub,Lewis Gavin A,Ainslie Mark,Schelbert Erik B,Davis Daniel M,Schmitt Matthias,Fildes James E,Miller Christopher A European heart journal Aims:Investigators have proposed that cardiovascular magnetic resonance (CMR) should have restrictions similar to those of ionizing imaging techniques. We aimed to investigate the acute effect of 1.5 T CMR on leucocyte DNA integrity, cell counts, and function in vitro, and in a large cohort of patients in vivo. Methods and results:In vitro study: peripheral blood mononuclear cells (PBMCs) were isolated from healthy volunteers, and histone H2AX phosphorylation (γ-H2AX) expression, leucocyte counts, and functional parameters were quantified using flow cytometry under the following conditions: (i) immediately following PBMC isolation, (ii) after standing on the benchside as a temperature and time control, (iii) after a standard CMR scan. In vivo study: blood samples were taken from 64 consecutive consenting patients immediately before and after a standard clinical scan. Samples were analysed for γ-H2AX expression and leucocyte counts. CMR was not associated with a significant change in γ-H2AX expression in vitro or in vivo, although there were significant inter-patient variations. In vitro cell integrity and function did not change with CMR. There was a significant reduction in circulating T cells in vivo following CMR. Conclusion:1.5 T CMR was not associated with DNA damage in vitro or in vivo. Histone H2AX phosphorylation expression varied markedly between individuals; therefore, small studies using γ-H2AX as a marker of DNA damage should be interpreted with caution. Cardiovascular magnetic resonance was not associated with loss of leucocyte viability or function in vitro. Cardiovascular magnetic resonance was associated with a statistically significant reduction in viable leucocytes in vivo. 10.1093/eurheartj/ehx646
    Endothelial cell apoptosis in obstructive sleep apnea: a link to endothelial dysfunction. El Solh Ali A,Akinnusi Morohunfolu E,Baddoura Fadi H,Mankowski Corey R American journal of respiratory and critical care medicine RATIONALE:Patients with obstructive sleep apnea (OSA) are at increased risk for cardiovascular diseases. Injury of endothelial cells has been advanced as an initial trigger to atherosclerosis. OBJECTIVES:To study the association between circulating apoptotic endothelial cells and vasomotor dysfunction as a function of sleep apnea. METHODS:Brachial artery flow-mediated dilation was determined in 14 subjects with documented OSA and 10 healthy control subjects at baseline and 8 weeks after continuous positive airway pressure (CPAP) therapy. Quantification of circulating apoptotic endothelial cells (CD146(+) Annexin V(+)) was performed by flow cytometry. MEASUREMENTS AND MAIN RESULTS:Compared with healthy subjects, patients with OSA had higher numbers of circulating CD146(+) Annexin V(+) cells (39.2 +/- 13.6 cells/mL and 17.8 +/- 9.4, respectively; p < 0.001). Increased apoptotic endothelial cells correlated moderately with abnormal vascular function (r = -0.61; p = 0.001). A significant correlation was observed between CD146 Annexin V(+) cells and the apnea-hypopnea index (r = 0.56; p = 0.004). After 8 weeks of treatment with CPAP, the numbers of circulating apoptotic endothelial cells were reduced significantly from 39.2 +/- 13.6 to 22.3 +/- 12.9 apoptotic cells per milliliter (p < 0.001) and correlated with improvement in endothelium-dependent vasodilation (r = 0.49; p = 0.07). CONCLUSIONS:In patients with OSA, impairment of endothelial-dependent vasodilation correlated with the degree of endothelial cell apoptosis. CPAP therapy led to significant decline in circulating apoptotic endothelial cells. These findings provide an additional mechanism for the predisposition of patients with OSA to premature vascular disease. 10.1164/rccm.200611-1598OC
    An Inhibitor of GSK3B and HDACs Kills Pancreatic Cancer Cells and Slows Pancreatic Tumor Growth and Metastasis in Mice. Edderkaoui Mouad,Chheda Chintan,Soufi Badr,Zayou Fouzia,Hu Robert W,Ramanujan V Krishnan,Pan Xinlei,Boros Laszlo G,Tajbakhsh Jian,Madhav Anisha,Bhowmick Neil A,Wang Qiang,Lewis Michael,Tuli Richard,Habtezion Aida,Murali Ramachandran,Pandol Stephen J Gastroenterology BACKGROUND & AIMS:Growth, progression, and drug resistance of pancreatic ductal adenocarcinomas (PDACs) have been associated with increased levels and activity of glycogen synthase kinase 3 beta (GSK3B) and histone deacetylases (HDACs). We designed and synthesized molecules that simultaneously inhibit the activities of both enzymes. We tested the effects of one of these molecules, Metavert, in pancreatic cancer cells and mice with pancreatic tumors. METHODS:We tested the ability of Metavert to bind GSK3B and HDACs using surface plasmon resonance. MIA PaCa-2, Bx-PC3, HPAF-II, and HPDE6 cell lines were incubated with different concentrations of Metavert, with or without paclitaxel or gemcitabine, or with other inhibitors of GSK3B and HDACs; cells were analyzed for apoptosis and migration and by immunoblotting, immunofluorescence, and real-time polymerase chain reaction. Krasþ/LSLG12D;Trp53þ/LSLR172H;Pdx-1-Cre (KPC) mice (2 months old) were given injections of Metavert (5 mg/kg, 3 times/week) or vehicle (control). B6.129J mice with tumors grown from UN-KPC961-Luc cells were given injections of Metavert or vehicle. Tumors and metastases were counted and pancreata were analyzed by immunohistochemistry. Glucose metabolism was measured using 13C-glucose tracer and mass spectroscopy and flow cytometry. Cytokine levels in blood samples were measured using multiplexing enzyme-linked immunosorbent assay. RESULTS:Metavert significantly reduced survival of PDAC cells but not nontransformed cells; the agent reduced markers of the epithelial-to-mesenchymal transition and stem cells in PDAC cell lines. Cells incubated with Metavert in combination with irradiation and paclitaxel or gemcitabine had reduced survival compared with cells incubated with either agent alone; Metavert increased killing of drug-resistant PDAC cells by paclitaxel and gemcitabine. PDAC cells incubated with Metavert acquired normalized glucose metabolism. Administration of Metavert (alone or in combination with gemcitibine) to KPC mice or mice with syngeneic tumors significantly increased their survival times, slowed tumor growth, prevented tumor metastasis, decreased tumor infiltration by tumor-associated macrophages, and decreased blood levels of cytokines. CONCLUSIONS:In studies of PDAC cells and 2 mouse models of PDAC, we found a dual inhibitor of GSK3B and HDACs (Metavert) to induce cancer cell apoptosis, reduce migration and expression of stem cell markers, and slow growth of tumors and metastases. Metavert had synergistic effects with gemcitabine. 10.1053/j.gastro.2018.08.028
    A transient reporter for editing enrichment (TREE) in human cells. Standage-Beier Kylie,Tekel Stefan J,Brookhouser Nicholas,Schwarz Grace,Nguyen Toan,Wang Xiao,Brafman David A Nucleic acids research Current approaches to identify cell populations that have been modified with deaminase base editing technologies are inefficient and rely on downstream sequencing techniques. In this study, we utilized a blue fluorescent protein (BFP) that converts to green fluorescent protein (GFP) upon a C-to-T substitution as an assay to report directly on base editing activity within a cell. Using this assay, we optimize various base editing transfection parameters and delivery strategies. Moreover, we utilize this assay in conjunction with flow cytometry to develop a transient reporter for editing enrichment (TREE) to efficiently purify base-edited cell populations. Compared to conventional cell enrichment strategies that employ reporters of transfection (RoT), TREE significantly improved the editing efficiency at multiple independent loci, with efficiencies approaching 80%. We also employed the BFP-to-GFP conversion assay to optimize base editor vector design in human pluripotent stem cells (hPSCs), a cell type that is resistant to genome editing and in which modification via base editors has not been previously reported. At last, using these optimized vectors in the context of TREE allowed for the highly efficient editing of hPSCs. We envision TREE as a readily adoptable method to facilitate base editing applications in synthetic biology, disease modeling, and regenerative medicine. 10.1093/nar/gkz713
    Heritability and genetic basis of protein level variation in an outbred population. Parts Leopold,Liu Yi-Chun,Tekkedil Manu M,Steinmetz Lars M,Caudy Amy A,Fraser Andrew G,Boone Charles,Andrews Brenda J,Rosebrock Adam P Genome research The genetic basis of heritable traits has been studied for decades. Although recent mapping efforts have elucidated genetic determinants of transcript levels, mapping of protein abundance has lagged. Here, we analyze levels of 4084 GFP-tagged yeast proteins in the progeny of a cross between a laboratory and a wild strain using flow cytometry and high-content microscopy. The genotype of trans variants contributed little to protein level variation between individual cells but explained >50% of the variance in the population's average protein abundance for half of the GFP fusions tested. To map trans-acting factors responsible, we performed flow sorting and bulk segregant analysis of 25 proteins, finding a median of five protein quantitative trait loci (pQTLs) per GFP fusion. Further, we find that cis-acting variants predominate; the genotype of a gene and its surrounding region had a large effect on protein level six times more frequently than the rest of the genome combined. We present evidence for both shared and independent genetic control of transcript and protein abundance: More than half of the expression QTLs (eQTLs) contribute to changes in protein levels of regulated genes, but several pQTLs do not affect their cognate transcript levels. Allele replacements of genes known to underlie trans eQTL hotspots confirmed the correlation of effects on mRNA and protein levels. This study represents the first genome-scale measurement of genetic contribution to protein levels in single cells and populations, identifies more than a hundred trans pQTLs, and validates the propagation of effects associated with transcript variation to protein abundance. 10.1101/gr.170506.113
    Viral load reduction improves activation and function of natural killer cells in patients with chronic hepatitis B. Tjwa Eric T T L,van Oord Gertine W,Hegmans Joost P,Janssen Harry L A,Woltman Andrea M Journal of hepatology BACKGROUND & AIMS:Natural killer (NK) cells play a major role in anti-viral immunity as first line defense and regulation of virus-specific T cell responses. This study aimed to investigate phenotype and function of NK cells in patients with chronic hepatitis B virus (HBV) infection and to study the effect of anti-viral therapy. METHODS:Peripheral blood NK cells from 40 chronic HBV patients were compared to NK cells of 25 healthy controls. The effect of entecavir-induced viral load reduction on NK cell phenotype and function was investigated in 15 chronic HBV patients. RESULTS:NK cell numbers and subset distribution did not differ between HBV patients and normal subjects. In chronic HBV patients, the cytotoxic capacity was retained, but NK cell activation and subsequent IFNγ and TNFα production, especially of the CD56(dim) subset, were strongly hampered. This functional dichotomy was paralleled by an altered activation state, elevated expression of NKG2A, and downregulated expression of CD16 and NKp30, which correlated with serum HBV-DNA load. Anti-viral therapy partially restored NK cell phenotype, as shown by NKG2A downregulation. Moreover, viral replication inhibition improved IFNγ production as a result of an increased ability of CD56(dim) NK cells to become activated de novo. This improved NK cell activation and function which correlated with therapy-induced reduction in serum ALT levels, but not HBV-DNA load. CONCLUSIONS:The specific defect in CD56(dim) NK cell activation and the reduced capacity to produce anti-viral and Th1-skewing cytokines may play a role in HBV persistence. Restoration of this NK cell cytokine-producing capacity, as achieved by viral load reduction, could therefore contribute to definite clearance of the virus. 10.1016/j.jhep.2010.07.009
    Nongenetic method for purifying stem cell-derived cardiomyocytes. Hattori Fumiyuki,Chen Hao,Yamashita Hiromi,Tohyama Shugo,Satoh Yu-Suke,Yuasa Shinsuke,Li Weizhen,Yamakawa Hiroyuki,Tanaka Tomofumi,Onitsuka Takeshi,Shimoji Kenichiro,Ohno Yohei,Egashira Toru,Kaneda Ruri,Murata Mitsushige,Hidaka Kyoko,Morisaki Takayuki,Sasaki Erika,Suzuki Takeshi,Sano Motoaki,Makino Shinji,Oikawa Shinzo,Fukuda Keiichi Nature methods Several applications of pluripotent stem cell (PSC)-derived cardiomyocytes require elimination of undifferentiated cells. A major limitation for cardiomyocyte purification is the lack of easy and specific cell marking techniques. We found that a fluorescent dye that labels mitochondria, tetramethylrhodamine methyl ester perchlorate, could be used to selectively mark embryonic and neonatal rat cardiomyocytes, as well as mouse, marmoset and human PSC-derived cardiomyocytes, and that the cells could subsequently be enriched (>99% purity) by fluorescence-activated cell sorting. Purified cardiomyocytes transplanted into testes did not induce teratoma formation. Moreover, aggregate formation of PSC-derived cardiomyocytes through homophilic cell-cell adhesion improved their survival in the immunodeficient mouse heart. Our approaches will aid in the future success of using PSC-derived cardiomyocytes for basic and clinical applications. 10.1038/nmeth.1403
    Sorting cardiomyocytes: a simple solution after all? Mummery Christine Nature methods 10.1038/nmeth0110-40
    Identification of a cKit(+) colonic crypt base secretory cell that supports Lgr5(+) stem cells in mice. Rothenberg Michael E,Nusse Ysbrand,Kalisky Tomer,Lee John J,Dalerba Piero,Scheeren Ferenc,Lobo Neethan,Kulkarni Subhash,Sim Sopheak,Qian Dalong,Beachy Philip A,Pasricha Pankaj J,Quake Stephen R,Clarke Michael F Gastroenterology BACKGROUND & AIMS:Paneth cells contribute to the small intestinal niche of Lgr5(+) stem cells. Although the colon also contains Lgr5(+) stem cells, it does not contain Paneth cells. We investigated the existence of colonic Paneth-like cells that have a distinct transcriptional signature and support Lgr5(+) stem cells. METHODS:We used multicolor fluorescence-activated cell sorting to isolate different subregions of colon crypts, based on known markers, from dissociated colonic epithelium of mice. We performed multiplexed single-cell gene expression analysis with quantitative reverse transcriptase polymerase chain reaction followed by hierarchical clustering analysis to characterize distinct cell types. We used immunostaining and fluorescence-activated cell sorting analyses with in vivo administration of a Notch inhibitor and in vitro organoid cultures to characterize different cell types. RESULTS:Multicolor fluorescence-activated cell sorting could isolate distinct regions of colonic crypts. Four major epithelial subtypes or transcriptional states were revealed by gene expression analysis of selected populations of single cells. One of these, the goblet cells, contained a distinct cKit/CD117(+) crypt base subpopulation that expressed Dll1, Dll4, and epidermal growth factor, similar to Paneth cells, which were also marked by cKit. In the colon, cKit(+) goblet cells were interdigitated with Lgr5(+) stem cells. In vivo, this colonic cKit(+) population was regulated by Notch signaling; administration of a γ-secretase inhibitor to mice increased the number of cKit(+) cells. When isolated from mouse colon, cKit(+) cells promoted formation of organoids from Lgr5(+) stem cells, which expressed Kitl/stem cell factor, the ligand for cKit. When organoids were depleted of cKit(+) cells using a toxin-conjugated antibody, organoid formation decreased. CONCLUSIONS:cKit marks small intestinal Paneth cells and a subset of colonic goblet cells that are regulated by Notch signaling and support Lgr5(+) stem cells. 10.1053/j.gastro.2012.02.006
    High maternal expression of SIGLEC1 on monocytes as a surrogate marker of a type I interferon signature is a risk factor for the development of autoimmune congenital heart block. Lisney Anna R,Szelinski Franziska,Reiter Karin,Burmester Gerd R,Rose Thomas,Dörner Thomas Annals of the rheumatic diseases OBJECTIVES:Autoimmune congenital heart block (CHB) is associated with placental transcytosis of maternal autoantibodies directed against Ro/SS-A and La/SS-B. However, only about 2% of children born to mothers with the respective antibodies are affected, indicating that further risk factors exist, which are not yet fully understood. In this study, we investigated whether a maternal type I interferon (IFN) signature represents a risk factor for the development of CHB. METHODS:Blood samples, clinical data and serological parameters from 9 women with CHB pregnancies, 14 pregnant women with antibodies against Ro/SS-A but without a CHB complication and another 30 healthy pregnant women as controls were studied. SIGLEC1 expression was measured by flow cytometry and was correlated to plasma IFN-α levels measured by ELISA, and IFN-γ-induced protein 10 (IP-10) levels measured by Bio-Plex technique. RESULTS:Mothers of affected children had a significantly higher expression of SIGLEC1 (p=0.0034) and IFN-α (p=0.014), but not of IP-10 (p=0.14, all MWU) compared to mothers of unaffected children. SIGLEC1 and IFN-α expression were reduced by hydroxychloroquine and oral glucocorticoids. CONCLUSIONS:High expression of SIGLEC1 in pregnant women with autoantibodies against Ro/SS-A indicates an enhanced risk for CHB development, and these women may benefit especially from IFN-α directed therapy, for example with hydroxychloroquine. 10.1136/annrheumdis-2016-210927
    The mucosal addressin cell adhesion molecule antibody PF-00547,659 in ulcerative colitis: a randomised study. Vermeire Séverine,Ghosh Subrata,Panes Julian,Dahlerup Jens F,Luegering Andreas,Sirotiakova Jana,Strauch Ulrike,Burgess Gary,Spanton Jacqueline,Martin Steven W,Niezychowski Wojciech Gut BACKGROUND AND AIMS:Leucocyte migration to gut mucosa, mediated by integrin binding to mucosal addressin cell adhesion molecule (MAdCAM), is a promising target for therapeutic intervention in inflammatory bowel disease. This first-in-human study of a monoclonal antibody to MAdCAM, PF-00547,659, aimed to explore the safety and preliminary efficacy of this gut-specific mechanism in ulcerative colitis. METHODS:In this randomised, double-blind placebo-controlled study, 80 patients with active ulcerative colitis received single or multiple (three doses, 4-week intervals) doses of PF-00547,659 0.03-10 mg/kg IV/SC, or placebo. Safety was assessed by adverse events, laboratory tests, and immunogenicity. Exploratory efficacy analyses were based on Mayo score and endoscopic responder rates at weeks 4 and 12. Faecal calprotectin was quantified as a measure of disease activity, and the number of α₄β₇⁺ lymphocytes was measured to demonstrate drug activity. RESULTS:No obvious drug-related side effects were observed in the PF-00547,659 group, while patient numbers, especially those fully exposed, were small. Overall responder/remission rates at 4 and 12 weeks were 52%/13% and 42%/22%, respectively with combined PF-00547,659 doses compared with 32%/11% and 21%/0%, respectively with placebo. Equivalent endoscopic responder rates were 50% and 42% versus 26% and 29%, respectively. Faecal calprotectin levels decreased to a greater extent with PF-00547,659 than placebo (week 4: 63% vs 18%). Despite variability, there was a trend for an increase in α₄β₇⁺ lymphocytes in patients receiving PF-00547,659. CONCLUSIONS:The favourable short-term safety profile and preliminary efficacy findings for PF-00547,659 in this first-in-human study pave the way for further investigation in larger trials, to establish the role of PF-00547,659 in ulcerative colitis treatment. Trial Register No: NCT00928681. 10.1136/gut.2010.226548
    Direct comparison of different stem cell types and subpopulations reveals superior paracrine potency and myocardial repair efficacy with cardiosphere-derived cells. Li Tao-Sheng,Cheng Ke,Malliaras Konstantinos,Smith Rachel Ruckdeschel,Zhang Yiqiang,Sun Baiming,Matsushita Noriko,Blusztajn Agnieszka,Terrovitis John,Kusuoka Hideo,Marbán Linda,Marbán Eduardo Journal of the American College of Cardiology OBJECTIVES:The goal of this study was to conduct a direct head-to-head comparison of different stem cell types in vitro for various assays of potency and in vivo for functional myocardial repair in the same mouse model of myocardial infarction. BACKGROUND:Adult stem cells of diverse origins (e.g., bone marrow, fat, heart) and antigenic identity have been studied for repair of the damaged heart, but the relative utility of the various cell types remains unclear. METHODS:Human cardiosphere-derived cells (CDCs), bone marrow-derived mesenchymal stem cells, adipose tissue-derived mesenchymal stem cells, and bone marrow mononuclear cells were compared. RESULTS:CDCs revealed a distinctive phenotype with uniform expression of CD105, partial expression of c-kit and CD90, and negligible expression of hematopoietic markers. In vitro, CDCs showed the greatest myogenic differentiation potency, highest angiogenic potential, and relatively high production of various angiogenic and antiapoptotic-secreted factors. In vivo, injection of CDCs into the infarcted mouse hearts resulted in superior improvement of cardiac function, the highest cell engraftment and myogenic differentiation rates, and the least-abnormal heart morphology 3 weeks after treatment. CDC-treated hearts also exhibited the lowest number of apoptotic cells. The c-kit(+) subpopulation purified from CDCs produced lower levels of paracrine factors and inferior functional benefit when compared with unsorted CDCs. To validate the comparison of cells from various human donors, selected results were confirmed in cells of different types derived from individual rats. CONCLUSIONS:CDCs exhibited a balanced profile of paracrine factor production and, among various comparator cell types/subpopulations, provided the greatest functional benefit in experimental myocardial infarction. 10.1016/j.jacc.2011.11.029
    Venetoclax for Patients With Chronic Lymphocytic Leukemia With 17p Deletion: Results From the Full Population of a Phase II Pivotal Trial. Stilgenbauer Stephan,Eichhorst Barbara,Schetelig Johannes,Hillmen Peter,Seymour John F,Coutre Steven,Jurczak Wojciech,Mulligan Stephen P,Schuh Anna,Assouline Sarit,Wendtner Clemens-Martin,Roberts Andrew W,Davids Matthew S,Bloehdorn Johannes,Munir Talha,Böttcher Sebastian,Zhou Lang,Salem Ahmed Hamed,Desai Monali,Chyla Brenda,Arzt Jennifer,Kim Su Young,Verdugo Maria,Gordon Gary,Hallek Michael,Wierda William G Journal of clinical oncology : official journal of the American Society of Clinical Oncology Purpose Venetoclax is an orally bioavailable B-cell lymphoma 2 inhibitor. US Food and Drug Administration and European Medicines Agency approval for patients with 17p deleted relapsed/refractory chronic lymphocytic leukemia [del(17p) CLL] was based on results from 107 patients. An additional 51 patients were enrolled in a safety expansion cohort. Extended analysis of all enrolled patients, including the effect of minimal residual disease (MRD) negativity on outcome, is now reported. Patients and Methods Overall, 158 patients with relapsed/refractory or previously untreated (n = 5) del(17p) CLL received venetoclax 400 mg per day after an initial dose ramp up. Responses were based on 2008 International Workshop on Chronic Lymphocytic Leukemia criteria, with monthly physical exams and blood counts. Computed tomography scan was mandatory at week 36, after which assessment made was by clinical evaluation. Marrow biopsy was performed when complete remission was suspected. MRD was assessed by flow cytometry. Results Patients had a median of two prior therapies (range, zero to 10 therapies), 71% had TP53 mutation, and 48% had nodes that were ≥ 5 cm. Median time on venetoclax was 23.1 months (range, 0 to 44.2 months) and median time on study was 26.6 months (range, 0 to 44.2 months). For all patients, investigator-assessed objective response rate was 77% (122 of 158 patients; 20% complete remission) and estimated progression-free survival at 24 months was 54% (95% CI, 45% to 62%). For 16 patients who received prior kinase inhibitors, objective response rate was 63% (10 of 16 patients) and 24-month progression-free survival estimate was 50% (95% CI, 25% to 71%). By intent-to-treat analysis, 48 (30%) of 158 patients achieved MRD below the cutoff of 10 in blood. Common grade 3 and 4 adverse events were hematologic and managed with supportive care and/or dose adjustments. Conclusion Venetoclax achieves durable responses and was well tolerated in patients with del(17p) CLL. A high rate of blood MRD < 10 was achieved in this high-risk population. 10.1200/JCO.2017.76.6840
    Haematopoietic stem cells require a highly regulated protein synthesis rate. Signer Robert A J,Magee Jeffrey A,Salic Adrian,Morrison Sean J Nature Many aspects of cellular physiology remain unstudied in somatic stem cells, for example, there are almost no data on protein synthesis in any somatic stem cell. Here we set out to compare protein synthesis in haematopoietic stem cells (HSCs) and restricted haematopoietic progenitors. We found that the amount of protein synthesized per hour in HSCs in vivo was lower than in most other haematopoietic cells, even if we controlled for differences in cell cycle status or forced HSCs to undergo self-renewing divisions. Reduced ribosome function in Rpl24(Bst/+) mice further reduced protein synthesis in HSCs and impaired HSC function. Pten deletion increased protein synthesis in HSCs but also reduced HSC function. Rpl24(Bst/+) cell-autonomously rescued the effects of Pten deletion in HSCs; blocking the increase in protein synthesis, restoring HSC function, and delaying leukaemogenesis. Pten deficiency thus depletes HSCs and promotes leukaemia partly by increasing protein synthesis. Either increased or decreased protein synthesis impairs HSC function. 10.1038/nature13035
    Role of STAT5 in controlling cell survival and immunoglobulin gene recombination during pro-B cell development. Malin Stephen,McManus Shane,Cobaleda César,Novatchkova Maria,Delogu Alessio,Bouillet Philippe,Strasser Andreas,Busslinger Meinrad Nature immunology STAT5 and interleukin 7 (IL-7) signaling are thought to control B lymphopoiesis by regulating the expression of key transcription factors and by activating variable (V(H)) gene segments at the immunoglobulin heavy-chain (Igh) locus. Using conditional mutagenesis to delete the gene encoding the transcription factor STAT5, we demonstrate that the development of pro-B cells was restored by transgenic expression of the prosurvival protein Bcl-2, which compensated for loss of the antiapoptotic protein Mcl-1. Expression of the genes encoding the B cell-specification factor EBF1 and the B cell-commitment protein Pax5 as well as V(H) gene recombination were normal in STAT5- or IL-7 receptor alpha-chain (IL-7Ralpha)-deficient pro-B cells rescued by Bcl-2. STAT5-expressing pro-B cells contained little or no active chromatin at most V(H) genes. In contrast, rearrangements of the immunoglobulin-kappa light-chain locus (Igk) were more abundant in STAT5- or IL-7Ralpha-deficient pro-B cells. Hence, STAT5 and IL-7 signaling control cell survival and the developmental ordering of immunoglobulin gene rearrangements by suppressing premature Igk recombination in pro-B cells. 10.1038/ni.1827
    CXCR4 acts as a costimulator during thymic beta-selection. Trampont Paul C,Tosello-Trampont Annie-Carole,Shen Yuelei,Duley Amanda K,Sutherland Ann E,Bender Timothy P,Littman Dan R,Ravichandran Kodi S Nature immunology Passage through the beta-selection developmental checkpoint requires productive rearrangement of segments of the T cell antigen receptor-beta gene (Tcrb) and formation of a pre-TCR on the surface of CD4(-)CD8(-) thymocytes. How other receptors influence betabeta-selection is less well understood. Here we define a new role for the chemokine receptor CXCR4 during T cell development. CXCR4 functionally associated with the pre-TCR and influenced beta-selection by regulating the steady-state localization of immature thymocytes in thymic subregions, by facilitating optimal pre-TCR-induced survival signals, and by promoting thymocyte proliferation. We also characterize functionally relevant signaling molecules downstream of CXCR4 and the pre-TCR in thymocytes. Our data designate CXCR4 as a costimulator of the pre-TCR during beta-selection. 10.1038/ni.1830
    Transcriptional analysis of intracytoplasmically stained, FACS-purified cells by high-throughput, quantitative nuclease protection. Pechhold Susanne,Stouffer Melissa,Walker Gregory,Martel Ralph,Seligmann Bruce,Hang Yan,Stein Roland,Harlan David M,Pechhold Klaus Nature biotechnology Analyzing specialized cells in heterogeneous tissues is crucial for understanding organ function in health and disease. Thus far, however, there has been no convenient method for studying gene expression in cells purified by fluorescence-activated cell sorting (FACS) using intracellular markers. Here we show that the quantitative nuclease protection assay (qNPA) enables transcriptional analysis of intracytoplasmically stained cells sorted by FACS. Applying the method to mouse pancreatic islet-cell subsets, we detected both expected and unknown lineage-specific gene expression patterns. Some beta cells from pregnant animals were found to express Mafb, previously observed only in immature beta cells during embryonic development. The four 'housekeeping' genes tested were expressed in purified islet-cell subpopulations with a notable variability, dependent on both cell lineage and developmental stage. Application of qNPA to intracellularly stained, FACS-sorted cells should be broadly applicable to the analysis of gene expression in subpopulations of any heterogeneous tissue, including tumors. 10.1038/nbt.1579
    Quantitative diagnosis of malignant pleural effusions by single-cell mechanophenotyping. Tse Henry T K,Gossett Daniel R,Moon Yo Sup,Masaeli Mahdokht,Sohsman Marie,Ying Yong,Mislick Kimberly,Adams Ryan P,Rao Jianyu,Di Carlo Dino Science translational medicine Biophysical characteristics of cells are attractive as potential diagnostic markers for cancer. Transformation of cell state or phenotype and the accompanying epigenetic, nuclear, and cytoplasmic modifications lead to measureable changes in cellular architecture. We recently introduced a technique called deformability cytometry (DC) that enables rapid mechanophenotyping of single cells in suspension at rates of 1000 cells/s-a throughput that is comparable to traditional flow cytometry. We applied this technique to diagnose malignant pleural effusions, in which disseminated tumor cells can be difficult to accurately identify by traditional cytology. An algorithmic diagnostic scoring system was developed on the basis of quantitative features of two-dimensional distributions of single-cell mechanophenotypes from 119 samples. The DC scoring system classified 63% of the samples into two high-confidence regimes with 100% positive predictive value or 100% negative predictive value, and achieved an area under the curve of 0.86. This performance is suitable for a prescreening role to focus cytopathologist analysis time on a smaller fraction of difficult samples. Diagnosis of samples that present a challenge to cytology was also improved. Samples labeled as "atypical cells," which require additional time and follow-up, were classified in high-confidence regimes in 8 of 15 cases. Further, 10 of 17 cytology-negative samples corresponding to patients with concurrent cancer were correctly classified as malignant or negative, in agreement with 6-month outcomes. This study lays the groundwork for broader validation of label-free quantitative biophysical markers for clinical diagnoses of cancer and inflammation, which could help to reduce laboratory workload and improve clinical decision-making. 10.1126/scitranslmed.3006559
    Functional diversity of T-cell subpopulations in subacute and chronic hypersensitivity pneumonitis. Barrera Lourdes,Mendoza Felipe,Zuñiga Joaquín,Estrada Andrea,Zamora Ana C,Melendro Emma I,Ramírez Remedios,Pardo Annie,Selman Moisés American journal of respiratory and critical care medicine RATIONALE:Hypersensitivity pneumonitis (HP) exhibits a diverse outcome. Patients with acute/subacute HP usually improve, whereas patients with chronic disease often progress to fibrosis. However, the mechanisms underlying this difference are unknown. OBJECTIVES:To examine the T-cell profile from patients with subacute HP and chronic HP. METHODS:T cells were obtained by bronchoalveolar lavage from 25 patients with subacute HP, 30 patients with chronic HP, and 8 control subjects. T-cell phenotype and functional profile were evaluated by flow cytometry, cytometric bead array, and immunohistochemistry. MEASUREMENTS AND MAIN RESULTS:Patients with chronic HP showed higher CD4+:CD8+ ratio (median, 3.05; range, 0.3-15; subacute HP: median, 1.3; range, 0.1-10; control: median, 1.3; range, 0.7-2.0; P < 0.01), and a decrease of gammadeltaT cells (median, 2.0; range, 0.5-3.4; subacute HP: median, 10; range, 4.8-17; control: median, 15; range, 5-19; P < 0.01). Patients with chronic HP exhibited an increase in the terminally differentiated memory CD4+ and CD8+ T-cell subsets compared with patients with subacute HP (P < 0.05). However, memory cells from chronic HP showed lower IFN-gamma production and decreased cytotoxic activity by CD8+ T lymphocytes. Chronic HP displayed a Th2-like phenotype with increased CXCR4 expression (median, 6%; range, 1.7-36, vs. control subjects: median, 0.7%; range, 0.2-1.4; and subacute HP: median, 2.2%; range, 0.1-5.3; P < 0.01), and decreased CXCR3 expression (median, 4.3%; range, 1.4-25%, vs. subacute HP: median, 37%; range, 4.9-78%; P < 0.01). Likewise, supernatants from antigen-specific-stimulated cells from chronic HP produced higher levels of IL-4 (80 +/- 63 pg/ml vs. 25 +/- 7 pg/ml; P < 0.01), and lower levels of IFN-gamma (3,818 +/- 1671 pg/ml vs. 100 +/- 61 pg/ml; P < 0.01) compared with subacute HP. CONCLUSIONS:Our findings indicate that patients with chronic HP lose effector T-cell function and exhibit skewing toward Th2 activity, which may be implicated in the fibrotic response that characterizes this clinical form. 10.1164/rccm.200701-093OC
    Cellular DNA content and proliferative activity evaluated by flow cytometry versus histopathological and staging classifications in human bladder tumors. de Vita R,Forte D,Maggi F,Eleuteri P,Di Silverio F European urology Flow cytometric analysis of cellular DNA content was performed on 78 biopsy bladder samples obtained from 61 patients with bladder tumors. All 6 normal tissue samples and 1 benign papilloma exhibited a cytometrically diploid DNA distribution, while 39 of 60 bladder carcinomas exhibited at least one aneuploid cell subpopulation. Furthermore, 13 of 39 aneuploid tumors were characterized by the presence of more than one aneuploid cell subpopulation. The results indicate a significant relationship between cytometric ploidy and morphological classification and stage: the occurrence of subpopulations with abnormal DNA content is associated with the increase in differentiation grade and stage. A significant statistical difference in the survival pattern between the diploid and aneuploid groups was observed. The percent of S cells extracted from DNA content distribution histograms indicates a statistically significant difference (p less than 0.01) between normal tissue (3.7 +/- 1.8), diploid tumor (8.4 +/- 3.9) and aneuploid tumor (14.9 +/- 6.0). Moreover the percent of S-phase cells increases with grade in only the aneuploid subgroup. Our results suggest that cytometric parameters in association with morphological and clinical criteria can contribute to a more accurate characterization of bladder tumors in prognostic terms.
    The activating receptor NKp46 is essential for the development of type 1 diabetes. Gur Chamutal,Porgador Angel,Elboim Moran,Gazit Roi,Mizrahi Saar,Stern-Ginossar Noam,Achdout Hagit,Ghadially Hormas,Dor Yuval,Nir Tomer,Doviner Victoria,Hershkovitz Oren,Mendelson Michal,Naparstek Yaakov,Mandelboim Ofer Nature immunology The mechanism of action of natural killer (NK) cells in type 1 diabetes is still unknown. Here we show that the activating receptor NKp46 recognizes mouse and human ligands on pancreatic beta cells. NK cells appeared in the pancreas when insulitis progressed to type 1 diabetes, and NKp46 engagement by beta cells led to degranulation of NK cells. NKp46-deficient mice had less development of type 1 diabetes induced by injection of a low dose of streptozotocin. Injection of soluble NKp46 proteins into nonobese diabetic mice during the early phase of insulitis and the prediabetic stage prevented the development of type 1 diabetes. Our findings demonstrate that NKp46 is essential for the development of type 1 diabetes and highlight potential new therapeutic modalities for this disease. 10.1038/ni.1834
    CTLA-4 suppresses the pathogenicity of self antigen-specific T cells by cell-intrinsic and cell-extrinsic mechanisms. Ise Wataru,Kohyama Masako,Nutsch Katherine M,Lee Hyang Mi,Suri Anish,Unanue Emil R,Murphy Theresa L,Murphy Kenneth M Nature immunology The inhibitory immunoregulatory receptor CTLA-4 is critical in maintaining self-tolerance, but the mechanisms of its actions have remained controversial. Here we examined the antigen specificity of tissue-infiltrating CD4(+) T cells in Ctla4(-/-) mice. After adoptive transfer, T cells isolated from tissues of Ctla4(-/-) mice showed T cell antigen receptor (TCR)-dependent accumulation in the tissues from which they were derived, which suggested reactivity to tissue-specific antigens. We identified the pancreas-specific enzyme PDIA2 as an autoantigen in Ctla4(-/-) mice. CTLA-4 expressed either on PDIA2-specific effector cells or on regulatory T cells was sufficient to control tissue destruction mediated by PDIA2-specific T cells. Our results demonstrate that both cell-intrinsic and non-cell-autonomous actions of CTLA-4 operate to maintain T cell tolerance to a self antigen. 10.1038/ni.1835
    Mesenchymal progenitors distinct from satellite cells contribute to ectopic fat cell formation in skeletal muscle. Uezumi Akiyoshi,Fukada So-ichiro,Yamamoto Naoki,Takeda Shin'ichi,Tsuchida Kunihiro Nature cell biology Ectopic fat deposition in skeletal muscle is closely associated with several disorders, however, the origin of these adipocytes is not clear, nor is the mechanism of their formation. Satellite cells function as adult muscle stem cells but are proposed to possess multipotency. Here, we prospectively identify PDGFRalpha(+) mesenchymal progenitors as being distinct from satellite cells and located in the muscle interstitium. We show that, of the muscle-derived cell populations, only PDGFRalpha(+) cells show efficient adipogenic differentiation both in vitro and in vivo. Reciprocal transplantations between regenerating and degenerating muscles, and co-culture experiments revealed that adipogenesis of PDGFRalpha(+) cells is strongly inhibited by the presence of satellite cell-derived myofibres. These results suggest that PDGFRalpha(+) mesenchymal progenitors are the major contributor to ectopic fat cell formation in skeletal muscle, and emphasize that interaction between muscle cells and PDGFRalpha(+) mesenchymal progenitors, not the fate decision of satellite cells, has a considerable impact on muscle homeostasis. 10.1038/ncb2014
    Hairy cell leukemia variant in a patient with chronic myeloid leukemia receiving nilotinib: sequential or coincidental? Gopaluni Srivalli,Sanyal Soma,Bair Alica,Vajpayee Neerja Journal of clinical oncology : official journal of the American Society of Clinical Oncology 10.1200/JCO.2011.38.1392
    Toll-like receptor signaling in small intestinal epithelium promotes B-cell recruitment and IgA production in lamina propria. Shang Limin,Fukata Masayuki,Thirunarayanan Nanthakumar,Martin Andrea P,Arnaboldi Paul,Maussang David,Berin Cecilia,Unkeless Jay C,Mayer Lloyd,Abreu Maria T,Lira Sergio A Gastroenterology BACKGROUND & AIMS:Several lines of evidence support a role for Toll-like receptor (TLR) signaling to protect the intestine from pathogenic infection. We hypothesized that TLR signaling at the level of the intestinal epithelium is critical for mucosal immune responses. METHODS:We generated transgenic mice that express a constitutively active form of TLR4 in the intestinal epithelium (V-TLR4 mice). Lamina propria cellularity was evaluated by immunostaining and flow cytometry. Immunoglobulin (Ig) A levels in the stool and serum were measured by enzyme-linked immunosorbent assay. Chemokine and cytokine expression were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS:V-TLR4 transgenic mice reproduced normally and had a normal life span. Constitutive activity of TLR4 in the intestinal epithelium promoted recruitment of B cells and an increase in fecal IgA levels. Intestinal epithelial cells of V-TLR4 mice expressed higher levels of CCL20 and CCL28, chemokines known to be involved in B-cell recruitment, and of a proliferation-inducing ligand (APRIL), a cytokine that promotes T-cell-independent class switching of B cells to IgA. The changes in B-cell numbers and IgA levels were blocked by simultaneous expression in intestinal epithelial cells of M3, a herpes virus protein that binds and inhibits multiple chemokines. CONCLUSIONS:TLR signaling in the intestinal epithelial cells significantly elevated the production of IgA in the intestine. This effect was mediated by TLR-induced expression of a specific set of chemokines and cytokines that promoted both recruitment of B cells into the lamina propria and IgA class switching of B cells. 10.1053/j.gastro.2008.04.020
    Muscle injury activates resident fibro/adipogenic progenitors that facilitate myogenesis. Joe Aaron W B,Yi Lin,Natarajan Anuradha,Le Grand Fabien,So Leslie,Wang Joy,Rudnicki Michael A,Rossi Fabio M V Nature cell biology Efficient tissue regeneration is dependent on the coordinated responses of multiple cell types. Here, we describe a new subpopulation of fibro/adipogenic progenitors (FAPs) resident in muscle tissue but arising from a distinct developmental lineage. Transplantation of purified FAPs results in the generation of ectopic white fat when delivered subcutaneously or intramuscularly in a model of fatty infiltration, but not in healthy muscle, suggesting that the environment controls their engraftment. These cells are quiescent in intact muscle but proliferate efficiently in response to damage. FAPs do not generate myofibres, but enhance the rate of differentiation of primary myogenic progenitors in co-cultivation experiments. In summary, FAPs expand upon damage to provide a transient source of pro-differentiation signals for proliferating myogenic progenitors. 10.1038/ncb2015
    Estrogen receptor analysis by flow cytometry. Van N T,Raber M,Barrows G H,Barlogie B Science (New York, N.Y.) A fluorescently labeled estradiol, N'-fluoresceino-N'-(17 beta-estradiol hemisuccinamide) thiourea (FE) was used for measuring estrogen receptor content per cell in tumor cells. The cellular content of FE was measured quantitatively by flow cytometry. Binding of FE occurs in the nanomolar concentration range, an indication of the high affinity of the labeled estradiol. Competition of FE for binding sites is observed with estrogens, but not with progestins, androgens, or glucocorticosteroids, indicating the specificity of FE binding. In contrast to other estrogen receptor assays, this new technique requires a small sample size (about 5000 cells) and permits the assessment of heterogeneity in estrogen receptor expression among tumor cells. 10.1126/science.6719116
    Induced pluripotent stem cell (iPSC)-derived Flk-1 progenitor cells engraft, differentiate, and improve heart function in a mouse model of acute myocardial infarction. Mauritz Christina,Martens Andreas,Rojas Sebastian V,Schnick Tilman,Rathert Christian,Schecker Natalie,Menke Sandra,Glage Silke,Zweigerdt Robert,Haverich Axel,Martin Ulrich,Kutschka Ingo European heart journal AIMS:Induced pluripotent stem cell (iPSC)-derived cardiovascular progenitor cells represent a suitable autologous cell source for myocardial regeneration as they have the capability to form myocardial cells and to contribute to revascularization. As a first proof of concept we evaluated the potential of a murine iPSC-derived cardiovascular progenitor population, which expresses the surface marker foetal liver kinase-1 (Flk-1), to restore myocardial tissue and improve cardiac function after acute myocardial infarction (MI) in mice. METHODS AND RESULTS:iPSC-derived Flk-1(pos) vs. Flk-1(neg) cells were selected by fluorescence activated cell sorting (FACS) and injected into the ischaemic myocardium of left anterior descending coronary artery (LAD)-ligated mice. Addressing safety aspects we used an octamer binding factor 4 (Oct4)-enhanced green fluorescent protein (eGFP) expressing iPSC clone from the transgenic Oct4-eGFP reporter mouse strain OG2 to enable FACS-based depletion of undifferentiated cells prior to transplantation. Infarcted animals were treated with placebo (phosphate-buffered saline, n = 13), Flk-1(neg) cells (n = 14), or Flk-1(pos) cells (n = 11; 5 × 10(5) cells each). Heart function was evaluated by magnetic resonance imaging and conductance catheter analysis 2 weeks postoperatively. Cardiovascular in vitro and in vivo differentiations were investigated by immunofluorescence staining. Treatment with Flk-1(pos) and Flk-1(neg) cells resulted in a favourable myocardial remodelling and improved left ventricular function. Engraftment and functional benefits were superior after transplantation of Flk-1(pos) compared with Flk-1(neg) cells. Furthermore, Flk-1(pos) grafts contained considerably more vascular structures in relation to Flk-1(neg) grafts. CONCLUSION:iPSC-derived Flk-1(pos) progenitor cells differentiate into cardiovascular lineages in vitro and in vivo and improve cardiac function after acute MI. This proof of concept study paves the way for an autologous iPSC-based therapy of MI. 10.1093/eurheartj/ehr166
    Multifunctional Theranostic Nanoparticles Based on Exceedingly Small Magnetic Iron Oxide Nanoparticles for T-Weighted Magnetic Resonance Imaging and Chemotherapy. Shen Zheyu,Chen Tianxiang,Ma Xuehua,Ren Wenzhi,Zhou Zijian,Zhu Guizhi,Zhang Ariel,Liu Yijing,Song Jibin,Li Zihou,Ruan Huimin,Fan Wenpei,Lin Lisen,Munasinghe Jeeva,Chen Xiaoyuan,Wu Aiguo ACS nano The recently emerged exceedingly small magnetic iron oxide nanoparticles (ES-MIONs) (<5 nm) are promising T-weighted contrast agents for magnetic resonance imaging (MRI) due to their good biocompatibility compared with Gd-chelates. However, the best particle size of ES-MIONs for T imaging is still unknown because the synthesis of ES-MIONs with precise size control to clarify the relationship between the r (or r/r) and the particle size remains a challenge. In this study, we synthesized ES-MIONs with seven different sizes below 5 nm and found that 3.6 nm is the best particle size for ES-MIONs to be utilized as T-weighted MR contrast agent. To enhance tumor targetability of theranostic nanoparticles and reduce the nonspecific uptake of nanoparticles by normal healthy cells, we constructed a drug delivery system based on the 3.6 nm ES-MIONs for T-weighted tumor imaging and chemotherapy. The laser scanning confocal microscopy (LSCM) and flow cytometry analysis results demonstrate that our strategy of precise targeting via exposure or hiding of the targeting ligand RGD on demand is feasible. The MR imaging and chemotherapy results on the cancer cells and tumor-bearing mice reinforce that our DOX@ES-MION3@RGD@mPEG3 nanoparticles are promising for high-resolution T-weighted MR imaging and precise chemotherapy of tumors. 10.1021/acsnano.7b04924
    Injectable living marrow stromal cell-based autologous tissue engineered heart valves: first experiences with a one-step intervention in primates. Weber Benedikt,Scherman Jacques,Emmert Maximilian Y,Gruenenfelder Juerg,Verbeek Renier,Bracher Mona,Black Melanie,Kortsmit Jeroen,Franz Thomas,Schoenauer Roman,Baumgartner Laura,Brokopp Chad,Agarkova Irina,Wolint Petra,Zund Gregor,Falk Volkmar,Zilla Peter,Hoerstrup Simon P European heart journal AIMS:A living heart valve with regeneration capacity based on autologous cells and minimally invasive implantation technology would represent a substantial improvement upon contemporary heart valve prostheses. This study investigates the feasibility of injectable, marrow stromal cell-based, autologous, living tissue engineered heart valves (TEHV) generated and implanted in a one-step intervention in non-human primates. METHODS AND RESULTS:Trileaflet heart valves were fabricated from non-woven biodegradable synthetic composite scaffolds and integrated into self-expanding nitinol stents. During the same intervention autologous bone marrow-derived mononuclear cells were harvested, seeded onto the scaffold matrix, and implanted transapically as pulmonary valve replacements into non-human primates (n = 6). The transapical implantations were successful in all animals and the overall procedure time from cell harvest to TEHV implantation was 118 ± 17 min. In vivo functionality assessed by echocardiography revealed preserved valvular structures and adequate functionality up to 4 weeks post implantation. Substantial cellular remodelling and in-growth into the scaffold materials resulted in layered, endothelialized tissues as visualized by histology and immunohistochemistry. Biomechanical analysis showed non-linear stress-strain curves of the leaflets, indicating replacement of the initial biodegradable matrix by living tissue. CONCLUSION:Here, we provide a novel concept demonstrating that heart valve tissue engineering based on a minimally invasive technique for both cell harvest and valve delivery as a one-step intervention is feasible in non-human primates. This innovative approach may overcome the limitations of contemporary surgical and interventional bioprosthetic heart valve prostheses. 10.1093/eurheartj/ehr059
    Extracellular redox modulation by regulatory T cells. Yan Zhonghua,Garg Sanjay K,Kipnis Jonathan,Banerjee Ruma Nature chemical biology We demonstrate that the mechanism of redox remodeling during mouse T-cell activation involves secretion of glutathione by dendritic cells and its subsequent cleavage to cysteine. Extracellular cysteine accumulation results in a lower redox potential, which is conducive to proliferation, and changes the net redox status of exofacial protein domains. Regulatory T cells inhibit this redox metabolite signaling pathway, which represents a previously unrecognized mechanism for immunosuppression of effector T cells. 10.1038/nchembio.212
    Application of phage display to high throughput antibody generation and characterization. Schofield Darren J,Pope Anthony R,Clementel Veronica,Buckell Jenny,Chapple Susan Dj,Clarke Kay F,Conquer Jennie S,Crofts Anna M,Crowther Sandra R E,Dyson Michael R,Flack Gillian,Griffin Gareth J,Hooks Yvette,Howat William J,Kolb-Kokocinski Anja,Kunze Susan,Martin Cecile D,Maslen Gareth L,Mitchell Joanne N,O'Sullivan Maureen,Perera Rajika L,Roake Wendy,Shadbolt S Paul,Vincent Karen J,Warford Anthony,Wilson Wendy E,Xie Jane,Young Joyce L,McCafferty John Genome biology We have created a high quality phage display library containing over 1010 human antibodies and describe its use in the generation of antibodies on an unprecedented scale. We have selected, screened and sequenced over 38,000 recombinant antibodies to 292 antigens, yielding over 7,200 unique clones. 4,400 antibodies were characterized by specificity testing and detailed sequence analysis and the data/clones are available online. Sensitive detection was demonstrated in a bead based flow cytometry assay. Furthermore, positive staining by immunohistochemistry on tissue microarrays was found for 37% (143/381) of antibodies. Thus, we have demonstrated the potential of and illuminated the issues associated with genome-wide monoclonal antibody generation. 10.1186/gb-2007-8-11-r254
    Prognostic value of immunophenotyping in multiple myeloma: a study by the PETHEMA/GEM cooperative study groups on patients uniformly treated with high-dose therapy. Mateo Gema,Montalbán M Angeles,Vidriales Maria-Belén,Lahuerta Juan J,Mateos Maria V,Gutiérrez Norma,Rosiñol Laura,Montejano Laura,Bladé Joan,Martínez Rafael,de la Rubia Javier,Diaz-Mediavilla Joaquín,Sureda Anna,Ribera José M,Ojanguren José M,de Arriba Felipe,Palomera Luis,Terol Maria J,Orfao Alberto,San Miguel Jesús F, , Journal of clinical oncology : official journal of the American Society of Clinical Oncology PURPOSE:To analyze the prognostic impact of immunophenotyping in patients with multiple myeloma (MM). PATIENTS AND METHODS:We have prospectively analyzed the prognostic impact of antigenic markers, assessed by multiparametric flow cytometry, in a series of 685 newly diagnosed MM patients that were uniformly treated according to the GEM 2000 protocol. RESULTS:Our results show that expression of both CD19 and CD28 as well as the absence of CD117 were associated with a significantly shorter progression free-survival (PFS) and overall survival (OS). Interestingly, the CD28 expression correlated with t(14;16) and del(17p), while CD117-negative patients were associated with t(4;14) and del(13q). Simultaneous assessment of CD28 and CD117 antigens allowed stratification of patients with MM into three risk categories: poor risk (CD28 positive CD117 negative), intermediate (either both markers negative or both positive), and good risk (CD28 negative CD117 positive), with PFS rates of 30, 37, and 45 months, respectively (P = .01), and OS rates of 45, 68, and not reached, respectively (P = .0001). CONCLUSION:To the best of our knowledge, this is the first prospective analysis in which the prognostic impact of a relatively high number of antigenic markers has been simultaneously analyzed in a large series of uniformly treated patients, showing that the expression of several antigens (particularly CD28 and CD117) on bone marrow plasma cells from patients with MM can help to identify patients at high risk of progression. 10.1200/JCO.2007.15.4120
    An Xp22 microdeletion associated with ocular albinism and ichthyosis: approximation of breakpoints and estimation of deletion size by using cloned DNA probes and flow cytometry. Schnur R E,Trask B J,van den Engh G,Punnett H H,Kistenmacher M,Tomeo M A,Naids R E,Nussbaum R L American journal of human genetics Ocular albinism of the Nettleship-Falls type (OA1) and X-linked ichthyosis (XI) due to steroid sulfatase (STS) deficiency are cosegregating in three cytogenetically normal half-brothers. The mother has patchy fundal hypopigmentation consistent with random X inactivation in an OA1 carrier. Additional phenotypic abnormalities that have been observed in other STS "deletion syndromes" are not present in this family. STS is entirely deleted on Southern blot in the affected males, but the loci MIC2X, DXS31, DXS143, DXS85, DXS43, DXS9, and DXS41 are not deleted. At least part of DXS278 is retained. Flow cytometric analysis of cultured lymphoblasts from one of the XI/OA1 males and his mother detected a deletion of about 3.5 million bp or about 2% of the X chromosome. Southern blot and RFLP analysis in the XI/OA1 family support the order tel-[STS-OA1-DXS278]-DXS9-DXS41-cen. An unrelated patient with the karyotype 46,X,t(X;Y) (p22;q11) retains the DXS143 locus on the derivative X chromosome but loses DXS278, suggesting that DXS278 is the more distal locus and is close to an XI/OA1 deletion boundary. If a contiguous gene deletion is responsible for the observed XI/OA1 phenotype, it localizes OA1 to the Xp22.3 region.
    Determination of antigen-specific memory/effector CD4+ T cell frequencies by flow cytometry: evidence for a novel, antigen-specific homeostatic mechanism in HIV-associated immunodeficiency. Waldrop S L,Pitcher C J,Peterson D M,Maino V C,Picker L J The Journal of clinical investigation The highly regulated secretion of effector cytokines by CD4+ T cells plays a critical role in immune protection against pathogens such as cytomegalovirus. Here, we directly compare the frequency and functional characteristics of cytomegalovirus-specific CD4+ memory/effector T cells in normal and HIV+ subjects using a novel, highly efficient multiparameter flow cytometric assay that detects the rapid intracellular accumulation of cytokine(s) after short-term (6 h) in vitro antigen stimulation. Responses in this assay correlate precisely with independent measures of sensitization history (e.g., seroreactivity), and allow the simultaneous assessment of multiple cytokines in single effector T cells. Healthy HIV- individuals manifested an average of 0.71, 0.72, 0.38, and 0.06% CD4+ T cells responding to cytomegalovirus with gamma-IFN, TNF-alpha, IL-2, and IL-4 production, respectively, with the simultaneous production of gamma-IFN, TNF-alpha, and IL-2 being the most common effector phenotype. Significantly, overall cytomegalovirus-specific CD4+ effector frequencies were markedly higher among 40% of HIV+ subjects (2.7-8.0%), and demonstrated a predominately polarized gamma-IFN+/TNF-alpha+/IL-2-/IL-4- phenotype. In contrast, CD4+ effector frequencies for heterologous, nonubiquitous viruses such as the mumps virus were low or absent in the HIV+ group. These data suggest the existence of homeostatic mechanisms in HIV disease that selectively preserve memory T cell populations reactive with ubiquitous pathogens such as cytomegalovirus-likely at the expense of T cell memory to more sporadically encountered infectious agents. 10.1172/JCI119338
    A Visible and Near-Infrared Light Activatable Diazocoumarin Probe for Fluorogenic Protein Labeling in Living Cells. Dai Sheng-Yao,Yang Dan Journal of the American Chemical Society Chemical modification of proteins in living cells permits valuable glimpses into the molecular interactions that underpin dynamic cellular events. While genetic engineering methods are often preferred, selective labeling of endogenous proteins in a complex intracellular milieu with chemical approaches represents a significant challenge. In this study, we report novel diazocoumarin compounds that can be photoactivated by visible (430-490 nm) and near-infrared light (800 nm) irradiation to photo-uncage reactive carbene intermediates, which could subsequently undergo an insertion reaction with concomitant fluorescence "turned on". With these new molecules in hand, we have developed a new approach for rapid, selective, and fluorogenic labeling of endogenous protein in living cells. By using CA-II and eDHFR as model proteins, we demonstrated that subcellular localization of proteins can be precisely visualized by live-cell imaging and protein levels can be reliably quantified in multiple cell types using flow cytometry. Dynamic protein regulations such as hypoxia-induced CA-IX accumulation can also be detected. In addition, by two-photon excitation with an 800 nm laser, cell-selective labeling can also be achieved with spatially controlled irradiation. Our method circumvents the cytotoxicity of UV light and obviates the need for introducing external reporters with "click chemistries". We believe that this approach of fluorescence labeling of endogenous protein by bioorthogonal photoirradiation opens up exciting opportunities for discoveries and mechanistic interrogation in chemical biology. 10.1021/jacs.0c08068
    Temporal changes in dendritic cell subsets, cross-priming and costimulation via CD70 control CD8(+) T cell responses to influenza. Ballesteros-Tato André,León Beatriz,Lund Frances E,Randall Troy D Nature immunology The question of which dendritic cells (DCs) respond to pulmonary antigens and cross-prime CD8(+) T cells remains controversial. We show here that influenza-specific CD8(+) T cell priming was controlled by different DCs at different times after infection. Whereas early priming was controlled by both CD103(+)CD11b(lo) and CD103(-)CD11b(hi) DCs, CD103(-)CD11b(hi) DCs dominated antigen presentation at the peak of infection. Moreover, CD103(-)CD11b(hi) DCs captured exogenous antigens in the lungs and directly cross-primed CD8(+) T cells in the draining lymph nodes without transferring antigen to CD8alpha(+) DCs. Finally, we show that CD103(-)CD11b(hi) DCs were the only DCs to express CD70 after influenza infection and that CD70 expression on CD103(-)CD11b(hi) DCs licensed them to expand CD8(+) T cell populations responding to both influenza and exogenous ovalbumin. 10.1038/ni.1838
    An essential role for the transcription factor HEB in thymocyte survival, Tcra rearrangement and the development of natural killer T cells. D'Cruz Louise M,Knell Jamie,Fujimoto Jessica K,Goldrath Ananda W Nature immunology E proteins are basic helix-loop-helix transcription factors that regulate many key aspects of lymphocyte development. Thymocytes express multiple E proteins that are thought to provide cooperative and compensatory functions crucial for T cell differentiation. Contrary to that, we report here that the E protein HEB was uniquely required at the CD4(+)CD8(+) double-positive (DP) stage of T cell development. Thymocytes lacking HEB showed impaired survival, failed to make rearrangements of variable-alpha (V(alpha)) segments to distal joining-alpha (J(alpha)) segments in the gene encoding the T cell antigen receptor alpha-chain (Tcra) and had a profound, intrinsic block in the development of invariant natural killer T cells (iNKT cells) at their earliest progenitor stage. Thus, our results show that HEB is a specific and essential factor in T cell development and in the generation of the iNKT cell lineage, defining a unique role for HEB in the regulation of lymphocyte maturation. 10.1038/ni.1845
    Evaluation of p53 protein expression in Barrett's esophagus by two-parameter flow cytometry. Ramel S,Reid B J,Sanchez C A,Blount P L,Levine D S,Neshat K,Haggitt R C,Dean P J,Thor K,Rabinovitch P S Gastroenterology Barrett's esophagus is a condition in which the normal stratified squamous epithelium is replaced by metaplastic columnar epithelium that predisposes to the development of esophageal adenocarcinoma. Neoplastic progression in Barrett's esophagus occurs by a multistep process associated with genomic instability and the development of aneuploid cell populations. p53 protein overexpression and allelic deletions on chromosome 17p have been shown to be present in some Barrett's adenocarcinomas, but the stage in neoplastic progression at which p53 protein overexpression develops has not been investigated. To determine the stages in neoplastic progression at which p53 protein overexpression could be detected, biopsy specimens from patients with Barrett's esophagus at all stages of histological progression from Barrett's metaplasia negative for dysplasia to esophageal adenocarcinoma were investigated using a multiparameter flow-cytometric assay. p53 protein overexpression was found in 1 of 21 patients (5%) with Barrett's metaplasia negative for dysplasia, 2 of 13 patients (15%) with Barrett's metaplasia with abnormalities in the indefinite/low-grade dysplasia range, 5 of 11 patients (45%) with high-grade dysplasia, and 8 of 15 patients (53%) with Barrett's adenocarcinoma (P less than 0.01). p53 protein overexpression was found in 9% of patients with Barrett's esophagus who had neither high-grade dysplasia nor adenocarcinoma. Whether or not patients whose biopsy specimens show p53 protein overexpression are at increased risk for progression to adenocarcinoma can be determined by prospective endoscopic surveillance.
    Fas determines differential fates of resident and recruited macrophages during resolution of acute lung injury. Janssen William J,Barthel Lea,Muldrow Alaina,Oberley-Deegan Rebecca E,Kearns Mark T,Jakubzick Claudia,Henson Peter M American journal of respiratory and critical care medicine RATIONALE:During acute lung injury (ALI) the macrophage pool expands markedly as inflammatory monocytes migrate from the circulation to the airspaces. As inflammation resolves, macrophage numbers return to preinjury levels and normal tissue structure and function are restored. OBJECTIVES:To determine the fate of resident and recruited macrophages during the resolution of ALI in mice and to elucidate the mechanisms responsible for macrophage removal. METHODS:ALI was induced in mice using influenza A (H1N1; PR8) infection and LPS instillation. Dye labeling techniques, bone marrow transplantation, and surface immunophenotyping were used to distinguish resident and recruited macrophages during inflammation and to study the role of Fas in determining macrophage fate during resolving ALI. MEASUREMENTS AND MAIN RESULTS:During acute and resolving lung injury from influenza A and LPS, a high proportion of the original resident alveolar macrophages persisted. In contrast, recruited macrophages exhibited robust accumulation in early inflammation, followed by a progressive decline in their number. This decline was mediated by apoptosis with local phagocytic clearance. Recruited macrophages expressed high levels of the death receptor Fas and were rapidly depleted from the airspaces by Fas-activating antibodies. In contrast, macrophage depletion was inhibited in mice treated with Fas-blocking antibodies and in chimeras with Fas-deficient bone marrow. Caspase-8 inhibition prevented macrophage apoptosis and delayed the resolution of ALI. CONCLUSIONS:These findings indicate that Fas-induced apoptosis of recruited macrophages is essential for complete resolution of ALI. 10.1164/rccm.201011-1891OC
    Transglutaminase 2 and its role in pulmonary fibrosis. Olsen Keith C,Sapinoro Ramil E,Kottmann R M,Kulkarni Ajit A,Iismaa Siiri E,Johnson Gail V W,Thatcher Thomas H,Phipps Richard P,Sime Patricia J American journal of respiratory and critical care medicine RATIONALE:Idiopathic pulmonary fibrosis (IPF) is a deadly progressive disease with few treatment options. Transglutaminase 2 (TG2) is a multifunctional protein, but its function in pulmonary fibrosis is unknown. OBJECTIVES:To determine the role of TG2 in pulmonary fibrosis. METHODS:The fibrotic response to bleomycin was compared between wild-type and TG2 knockout mice. Transglutaminase and transglutaminase-catalyzed isopeptide bond expression was examined in formalin-fixed human lung biopsy sections by immunohistochemistry from patients with IPF. In addition, primary human lung fibroblasts were used to study TG2 function in vitro. MEASUREMENTS AND MAIN RESULTS:TG2 knockout mice developed significantly reduced fibrosis compared with wild-type mice as determined by hydroxyproline content and histologic fibrosis score (P < 0.05). TG2 expression and activity are increased in lung biopsy sections in humans with IPF compared with normal control subjects. In vitro overexpression of TG2 led to increased fibronectin deposition, whereas transglutaminase knockdown led to defects in contraction and adhesion. The profibrotic cytokine transforming growth factor-β causes an increase in membrane-localized TG2, increasing its enzymatic activity. CONCLUSIONS:TG2 is involved in pulmonary fibrosis in a mouse model and in human disease and is important in normal fibroblast function. With continued research on TG2, it may offer a new therapeutic target. 10.1164/rccm.201101-0013OC
    Sept4/ARTS is required for stem cell apoptosis and tumor suppression. García-Fernández María,Kissel Holger,Brown Samara,Gorenc Travis,Schile Andrew J,Rafii Shahin,Larisch Sarit,Steller Hermann Genes & development Inhibitor of Apoptosis Proteins (IAPs) are frequently overexpressed in tumors and have become promising targets for developing anti-cancer drugs. IAPs can be inhibited by natural antagonists, but a physiological requirement of mammalian IAP antagonists remains to be established. Here we show that deletion of the mouse Sept4 gene, which encodes the IAP antagonist ARTS, promotes tumor development. Sept4-null mice have increased numbers of hematopoietic stem and progenitor cells, elevated XIAP protein, increased resistance to cell death, and accelerated tumor development in an Eμ-Myc background. These phenotypes are partially suppressed by inactivation of XIAP. Our results suggest that apoptosis plays an important role as a frontline defense against cancer by restricting the number of normal stem cells. 10.1101/gad.1970110
    Involvement of a chromatin remodeling complex in damage tolerance during DNA replication. Falbo Karina B,Alabert Constance,Katou Yuki,Wu Su,Han Junhong,Wehr Tammy,Xiao Jing,He Xiangwei,Zhang Zhiguo,Shi Yang,Shirahige Katsu,Pasero Philippe,Shen Xuetong Nature structural & molecular biology ATP-dependent chromatin remodeling complexes have been shown to participate in DNA replication in addition to transcription and DNA repair. However, the mechanisms of their involvement in DNA replication remain unclear. Here, we reveal a specific function of the yeast INO80 chromatin remodeling complex in the DNA damage tolerance pathways. Whereas INO80 is necessary for the resumption of replication at forks stalled by methyl methane sulfonate (MMS), it is not required for replication fork collapse after treatment with hydroxyurea (HU). Mechanistically, INO80 regulates DNA damage tolerance during replication through modulation of PCNA (proliferating cell nuclear antigen) ubiquitination and Rad51-mediated processing of recombination intermediates at impeded replication forks. Our findings establish a mechanistic link between INO80 and DNA damage tolerance pathways, indicating that chromatin remodeling is important for accurate DNA replication. 10.1038/nsmb.1686
    Sequential class switching is required for the generation of high affinity IgE antibodies. Xiong Huizhong,Dolpady Jayashree,Wabl Matthias,Curotto de Lafaille Maria A,Lafaille Juan J The Journal of experimental medicine IgE antibodies with high affinity for their antigens can be stably cross-linked at low concentrations by trace amounts of antigen, whereas IgE antibodies with low affinity bind their antigens weakly. In this study, we find that there are two distinct pathways to generate high and low affinity IgE. High affinity IgE is generated through sequential class switching (μ→γ→ε) in which an intermediary IgG phase is necessary for the affinity maturation of the IgE response, where the IgE inherits somatic hypermutations and high affinity from the IgG1 phase. In contrast, low affinity IgE is generated through direct class switching (μ→ε) and is much less mutated. Mice deficient in IgG1 production cannot produce high affinity IgE, even after repeated immunizations. We demonstrate that a small amount of high affinity IgE can cause anaphylaxis and is pathogenic. Low affinity IgE competes with high affinity IgE for binding to Fcε receptors and prevents anaphylaxis and is thus beneficial. 10.1084/jem.20111941
    Inhibiting the HSP90 chaperone destabilizes macrophage migration inhibitory factor and thereby inhibits breast tumor progression. Schulz Ramona,Marchenko Natalia D,Holembowski Lena,Fingerle-Rowson Günter,Pesic Marina,Zender Lars,Dobbelstein Matthias,Moll Ute M The Journal of experimental medicine Intracellular macrophage migration inhibitory factor (MIF) often becomes stabilized in human cancer cells. MIF can promote tumor cell survival, and elevated MIF protein correlates with tumor aggressiveness and poor prognosis. However, the molecular mechanism facilitating MIF stabilization in tumors is not understood. We show that the tumor-activated HSP90 chaperone complex protects MIF from degradation. Pharmacological inhibition of HSP90 activity, or siRNA-mediated knockdown of HSP90 or HDAC6, destabilizes MIF in a variety of human cancer cells. The HSP90-associated E3 ubiquitin ligase CHIP mediates the ensuing proteasome-dependent MIF degradation. Cancer cells contain constitutive endogenous MIF-HSP90 complexes. siRNA-mediated MIF knockdown inhibits proliferation and triggers apoptosis of cultured human cancer cells, whereas HSP90 inhibitor-induced apoptosis is overridden by ectopic MIF expression. In the ErbB2 transgenic model of human HER2-positive breast cancer, genetic ablation of MIF delays tumor progression and prolongs overall survival of mice. Systemic treatment with the HSP90 inhibitor 17AAG reduces MIF expression and blocks growth of MIF-expressing, but not MIF-deficient, tumors. Together, these findings identify MIF as a novel HSP90 client and suggest that HSP90 inhibitors inhibit ErbB2-driven breast tumor growth at least in part by destabilizing MIF. 10.1084/jem.20111117
    Genetic resistance to JAK2 enzymatic inhibitors is overcome by HSP90 inhibition. Weigert Oliver,Lane Andrew A,Bird Liat,Kopp Nadja,Chapuy Bjoern,van Bodegom Diederik,Toms Angela V,Marubayashi Sachie,Christie Amanda L,McKeown Michael,Paranal Ronald M,Bradner James E,Yoda Akinori,Gaul Christoph,Vangrevelinghe Eric,Romanet Vincent,Murakami Masato,Tiedt Ralph,Ebel Nicolas,Evrot Emeline,De Pover Alain,Régnier Catherine H,Erdmann Dirk,Hofmann Francesco,Eck Michael J,Sallan Stephen E,Levine Ross L,Kung Andrew L,Baffert Fabienne,Radimerski Thomas,Weinstock David M The Journal of experimental medicine Enzymatic inhibitors of Janus kinase 2 (JAK2) are in clinical development for the treatment of myeloproliferative neoplasms (MPNs), B cell acute lymphoblastic leukemia (B-ALL) with rearrangements of the cytokine receptor subunit cytokine receptor-like factor 2 (CRLF2), and other tumors with constitutive JAK2 signaling. In this study, we identify G935R, Y931C, and E864K mutations within the JAK2 kinase domain that confer resistance across a panel of JAK inhibitors, whether present in cis with JAK2 V617F (observed in MPNs) or JAK2 R683G (observed in B-ALL). G935R, Y931C, and E864K do not reduce the sensitivity of JAK2-dependent cells to inhibitors of heat shock protein 90 (HSP90), which promote the degradation of both wild-type and mutant JAK2. HSP90 inhibitors were 100-1,000-fold more potent against CRLF2-rearranged B-ALL cells, which correlated with JAK2 degradation and more extensive blockade of JAK2/STAT5, MAP kinase, and AKT signaling. In addition, the HSP90 inhibitor AUY922 prolonged survival of mice xenografted with primary human CRLF2-rearranged B-ALL further than an enzymatic JAK2 inhibitor. Thus, HSP90 is a promising therapeutic target in JAK2-driven cancers, including those with genetic resistance to JAK enzymatic inhibitors. 10.1084/jem.20111694
    FoxO1 induces Ikaros splicing to promote immunoglobulin gene recombination. Alkhatib Alabbas,Werner Markus,Hug Eva,Herzog Sebastian,Eschbach Cathrin,Faraidun Hemin,Köhler Fabian,Wossning Thomas,Jumaa Hassan The Journal of experimental medicine Somatic rearrangement of immunoglobulin (Ig) genes is a key step during B cell development. Using pro-B cells lacking the phosphatase Pten (phosphatase and tensin homolog), which negatively regulates phosphoinositide-3-kinase (PI3K) signaling, we show that PI3K signaling inhibits Ig gene rearrangement by suppressing the expression of the transcription factor Ikaros. Further analysis revealed that the transcription factor FoxO1 is crucial for Ikaros expression and that PI3K-mediated down-regulation of FoxO1 suppresses Ikaros expression. Interestingly, FoxO1 did not influence Ikaros transcription; instead, FoxO1 is essential for proper Ikaros mRNA splicing, as FoxO1-deficient cells contain aberrantly processed Ikaros transcripts. Moreover, FoxO1-induced Ikaros expression was sufficient only for proximal V(H) to DJ(H) gene rearrangement. Simultaneous expression of the transcription factor Pax5 was needed for the activation of distal V(H) genes; however, Pax5 did not induce any Ig gene rearrangement in the absence of Ikaros. Together, our results suggest that ordered Ig gene rearrangement is regulated by distinct activities of Ikaros, which mediates proximal V(H) to DJ(H) gene rearrangement downstream of FoxO1 and cooperates with Pax5 to activate the rearrangement of distal V(H) genes. 10.1084/jem.20110216
    Dose-adjusted EPOCH-rituximab combined with fludarabine provides an effective bridge to reduced-intensity allogeneic hematopoietic stem-cell transplantation in patients with lymphoid malignancies. Salit Rachel B,Fowler Daniel H,Wilson Wyndham H,Dean Robert M,Pavletic Steven Z,Dunleavy Kieron,Hakim Frances,Fry Terry J,Steinberg Seth M,Hughes Thomas E,Odom Jeanne,Bryant Kelly,Gress Ronald E,Bishop Michael R Journal of clinical oncology : official journal of the American Society of Clinical Oncology PURPOSE:There is currently no standard chemotherapy regimen for patients with lymphoid malignancies being considered for reduced-intensity conditioning allogeneic hematopoietic stem-cell transplantation (RIC-alloHSCT). The ideal regimen would provide disease control and result in lymphocyte depletion to facilitate engraftment. To this end, we developed a novel regimen by adding fludarabine to dose-adjusted continuous-infusion etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin plus with or without rituximab (DA-EPOCH-F/R). PATIENTS AND METHODS:One hundred forty-seven patients with lymphoid malignancy (median age, 50 years) who had heavily pretreated (median prior regimens, three) and chemo-refractory (47%) disease were treated with DA-EPOCH-F/R before RIC-alloHSCT. Patients received one to three consecutive cycles until achieving lymphocyte depletion (CD4(+) count < 200/μL) or progressive disease. RESULTS:Overall response rate was 41%; 39% of patients had stable disease. Toxicity included grade 4 neutropenia in 65% and thrombocytopenia in 25% of patients. DA-EPOCH-F/R resulted in lymphocyte depletion (P < .001), which was inversely associated with serum interleukin (IL) 7 and IL-15 levels. Of 147 patients, 143 patients proceeded to RIC-alloHSCT. Patients with lower CD3(+) (P < .001), CD4(+) (P < .001), and CD8(+) (P < .001) T-cell counts after DA-EPOCH-F/R were more likely to achieve full donor lymphoid chimerism by day +14 after transplant. Relative to nonresponders to DA-EPOCH-F/R, patients with complete and partial response had increased event-free survival (77.4 v 4.8 months; P < .001) and overall survival (98.5 v 16.2 months; P < .001). CONCLUSION:DA-EPOCH-F/R safely provides tumor cytoreduction and lymphocyte depletion, thereby offering a bridge to RIC-alloHSCT in patients with aggressive lymphoid malignancies. 10.1200/JCO.2011.37.0296
    Age, microbiota, and T cells shape diverse individual IgA repertoires in the intestine. Lindner Cornelia,Wahl Benjamin,Föhse Lisa,Suerbaum Sebastian,Macpherson Andrew J,Prinz Immo,Pabst Oliver The Journal of experimental medicine Intestinal immunoglobulin A (IgA) ensures host defense and symbiosis with our commensal microbiota. Yet previous studies hint at a surprisingly low diversity of intestinal IgA, and it is unknown to what extent the diverse Ig arsenal generated by somatic recombination and diversification is actually used. In this study, we analyze more than one million mouse IgA sequences to describe the shaping of the intestinal IgA repertoire, its determinants, and stability over time. We show that expanded and infrequent clones combine to form highly diverse polyclonal IgA repertoires with very little overlap between individual mice. Selective homing allows expanded clones to evenly seed the small but not large intestine. Repertoire diversity increases during aging in a dual process. On the one hand, microbiota-, T cell-, and transcription factor RORγt-dependent but Peyer's patch-independent somatic mutations drive the diversification of expanded clones, and on the other hand, new clones are introduced into the repertoire of aged mice. An individual's IgA repertoire is stable and recalled after plasma cell depletion, which is indicative of functional memory. These data provide a conceptual framework to understand the dynamic changes in the IgA repertoires to match environmental and intrinsic stimuli. 10.1084/jem.20111980
    STAT5 is a potent negative regulator of TFH cell differentiation. Johnston Robert J,Choi Youn Soo,Diamond Jeffrey A,Yang Jessica A,Crotty Shane The Journal of experimental medicine Follicular helper T cells (T(FH) cells) constitute the CD4(+) T cell subset that is specialized to provide help to germinal center (GC) B cells and, consequently, mediate the development of long-lived humoral immunity. T(FH) cell differentiation is driven by the transcription factor Bcl6, and recent studies have identified cytokine and cell-cell signals that drive Bcl6 expression. However, although T(FH) dysregulation is associated with several major autoimmune diseases, the mechanisms underlying the negative regulation of T(FH) cell differentiation are poorly understood. In this study, we show that STAT5 inhibits T(FH) cell differentiation and function. Constitutive STAT5 signaling in activated CD4(+) T cells selectively blocked T(FH) cell differentiation and GCs, and IL-2 signaling was a primary inducer of this pathway. Conversely, STAT5-deficient CD4(+) T cells (mature STAT5(fl/fl) CD4(+) T cells transduced with a Cre-expressing vector) rapidly up-regulated Bcl6 expression and preferentially differentiated into T(FH) cells during T cell priming in vivo. STAT5 signaling failed to inhibit T(FH) cell differentiation in the absence of the transcription factor Blimp-1, a direct repressor of Bcl6 expression and T(FH) cell differentiation. These results demonstrate that IL-2, STAT5, and Blimp-1 collaborate to negatively regulate T(FH) cell differentiation. 10.1084/jem.20111174
    Gene expression induced by Toll-like receptors in macrophages requires the transcription factor NFAT5. Buxadé Maria,Lunazzi Giulia,Minguillón Jordi,Iborra Salvador,Berga-Bolaños Rosa,Del Val Margarita,Aramburu José,López-Rodríguez Cristina The Journal of experimental medicine Toll-like receptors (TLRs) engage networks of transcriptional regulators to induce genes essential for antimicrobial immunity. We report that NFAT5, previously characterized as an osmostress responsive factor, regulates the expression of multiple TLR-induced genes in macrophages independently of osmotic stress. NFAT5 was essential for the induction of the key antimicrobial gene Nos2 (inducible nitric oxide synthase [iNOS]) in response to low and high doses of TLR agonists but is required for Tnf and Il6 mainly under mild stimulatory conditions, indicating that NFAT5 could regulate specific gene patterns depending on pathogen burden intensity. NFAT5 exhibited two modes of association with target genes, as it was constitutively bound to Tnf and other genes regardless of TLR stimulation, whereas its recruitment to Nos2 or Il6 required TLR activation. Further analysis revealed that TLR-induced recruitment of NFAT5 to Nos2 was dependent on inhibitor of κB kinase (IKK) β activity and de novo protein synthesis, and was sensitive to histone deacetylases. In vivo, NFAT5 was necessary for effective immunity against Leishmania major, a parasite whose clearance requires TLRs and iNOS expression in macrophages. These findings identify NFAT5 as a novel regulator of mammalian anti-pathogen responses. 10.1084/jem.20111569
    Regulation of hematopoietic stem cell differentiation by a single ubiquitin ligase-substrate complex. Reavie Linsey,Della Gatta Giusy,Crusio Kelly,Aranda-Orgilles Beatriz,Buckley Shannon M,Thompson Benjamin,Lee Eugine,Gao Jie,Bredemeyer Andrea L,Helmink Beth A,Zavadil Jiri,Sleckman Barry P,Palomero Teresa,Ferrando Adolfo,Aifantis Iannis Nature immunology Hematopoietic stem cell (HSC) differentiation is regulated by cell-intrinsic and cell-extrinsic cues. In addition to transcriptional regulation, post-translational regulation may also control HSC differentiation. To test this hypothesis, we visualized the ubiquitin-regulated protein stability of a single transcription factor, c-Myc. The stability of c-Myc protein was indicative of HSC quiescence, and c-Myc protein abundance was controlled by the ubiquitin ligase Fbw7. Fine changes in the stability of c-Myc protein regulated the HSC gene-expression signature. Using whole-genome genomic approaches, we identified specific regulators of HSC function directly controlled by c-Myc binding; however, adult HSCs and embryonic stem cells sensed and interpreted c-Myc-regulated gene expression in distinct ways. Our studies show that a ubiquitin ligase-substrate pair can orchestrate the molecular program of HSC differentiation. 10.1038/ni.1839
    Signaling by intrathymic cytokines, not T cell antigen receptors, specifies CD8 lineage choice and promotes the differentiation of cytotoxic-lineage T cells. Park Jung-Hyun,Adoro Stanley,Guinter Terry,Erman Batu,Alag Amala S,Catalfamo Marta,Kimura Motoko Y,Cui Yongzhi,Lucas Philip J,Gress Ronald E,Kubo Masato,Hennighausen Lothar,Feigenbaum Lionel,Singer Alfred Nature immunology Immature CD4(+)CD8(+) (double-positive (DP)) thymocytes are signaled via T cell antigen receptors (TCRs) to undergo positive selection and become responsive to intrathymic cytokines such as interleukin 7 (IL-7). We report here that cytokine signaling is required for positively selected thymocytes to express the transcription factor Runx3, specify CD8 lineage choice and differentiate into cytotoxic-lineage T cells. In DP thymocytes genetically engineered to be cytokine responsive, IL-7 signaling induced TCR-unsignaled DP thymocytes to express Runx3 and to differentiate into mature CD8(+) T cells, completely circumventing positive selection. We conclude that TCR-mediated positive selection converts DP cells into cytokine-responsive thymocytes, but it is subsequent signaling by intrathymic cytokines that specifies CD8 lineage choice and promotes differentiation into cytotoxic-lineage T cells. 10.1038/ni.1840
    Efficient mucosal vaccination mediated by the neonatal Fc receptor. Ye Lilin,Zeng Rongyu,Bai Yu,Roopenian Derry C,Zhu Xiaoping Nature biotechnology Almost all infectious diseases are initiated at mucosal surfaces, yet intramuscular or subcutaneous vaccination usually provides only minimal protection at sites of infection owing to suboptimal activation of the mucosal immune system. The neonatal Fc receptor (FcRn) mediates the transport of IgG across polarized epithelial cells lining mucosal surfaces. We mimicked this process by fusing a model antigen, herpes simplex virus type-2 (HSV-2) glycoprotein gD, to an IgG Fc fragment. Intranasal immunization, together with the adjuvant CpG, completely protected wild-type, but not FcRn knockout, mice after intravaginal challenge with virulent HSV-2 186. This immunization strategy induced efficient mucosal and systemic antibody, B- and T-cell immune responses, with stable protection for at least 6 months after vaccination in most of the immunized animals. The FcRn-IgG transcellular transport pathway may provide a general delivery route for subunit vaccines against many mucosal pathogens. 10.1038/nbt.1742
    Cell biologists sort things out: Analysis and purification of intracellular organelles by flow cytometry. Böck G,Steinlein P,Huber L A Trends in cell biology Flow cytometry was established originally for measuring DNA content and for the analysis of cell-surface markers in combination with cell sorting. During the past two decades, it has added new dimensions to various areas of immunology and medicine. Increased sensitivity and precision of flow cytometers, accompanied by the development of new fluorescent dyes and probes, has led to new applications in molecular cell biology and genetics. This article focuses on applications of flow cytometry in analysis and sorting of intracellular organelles. 10.1016/S0962-8924(97)01160-4
    Dual role of B cells with accelerated onset but reduced disease activity in P0₁₀₆₋₁₂₅-induced experimental autoimmune neuritis of IgH ⁰(/)⁰ mice. Brunn Anna,Utermöhlen Olaf,Sánchez-Ruiz Monica,Montesinos-Rongen Manuel,Blau Tobias,Schlüter Dirk,Deckert Martina Acta neuropathologica The role of B cells in autoimmune-mediated diseases of the peripheral nervous system was studied in experimental autoimmune neuritis (EAN) in B cell deficient IgH⁰(/)⁰ C57BL/6J mice having been immunized with P0₁₀₆₋₁₂₅ peptide. Compared to coisogenic IgH(+/+) mice, onset of EAN was accelerated [100% disease incidence at day 9 post immunization (p.i.) vs. day 15 p.i.]. At day 9 p.i., numbers of P0₁₀₆₋₁₂₅-specific interferon (IFN)-γ-producing CD4(+) T cells were increased, while IL-10 mRNA and production were decreased in IgH⁰(/)⁰ mice. Beyond day 9 p.i., declining disease activity and a significant reduction of maximal disease activity were correlated with significantly reduced numbers of IFN-γ-producing CD4(+) T cells in IgH(0/0) mice as compared with IgH(+/+) mice. Correspondingly, neuropathology demonstrated only mild axonal damage, while demyelination and dying back axonopathy with spinal cord motor neuron apoptosis were absent. Thus, depending on the stage of EAN, B cells play a dual, i.e. suppressive and enhancing, role during induction and at height of EAN, respectively. The combined interaction of B cells as well as CD4(+) and CD8(+) T cells is required for the development of EAN. 10.1007/s00401-010-0724-8
    Transforming growth factor-beta signaling curbs thymic negative selection promoting regulatory T cell development. Ouyang Weiming,Beckett Omar,Ma Qian,Li Ming O Immunity Thymus-derived naturally occurring regulatory T (nTreg) cells are necessary for immunological self-tolerance. nTreg cell development is instructed by the T cell receptor and can be induced by agonist antigens that trigger T cell-negative selection. How T cell deletion is regulated so that nTreg cells are generated is unclear. Here we showed that transforming growth factor-beta (TGF-beta) signaling protected nTreg cells and antigen-stimulated conventional T cells from apoptosis. Enhanced apoptosis of TGF-beta receptor-deficient nTreg cells was associated with high expression of proapoptotic proteins Bim, Bax, and Bak and low expression of the antiapoptotic protein Bcl-2. Ablation of Bim in mice corrected the Treg cell development and homeostasis defects. Our results suggest that nTreg cell commitment is independent of TGF-beta signaling. Instead, TGF-beta promotes nTreg cell survival by antagonizing T cell negative selection. These findings reveal a critical function for TGF-beta in control of autoreactive T cell fates with important implications for understanding T cell self-tolerance mechanisms. 10.1016/j.immuni.2010.04.012
    The transcription factor PU.1 controls dendritic cell development and Flt3 cytokine receptor expression in a dose-dependent manner. Carotta Sebastian,Dakic Aleksandar,D'Amico Angela,Pang Swee Heng Milon,Greig Kylie T,Nutt Stephen L,Wu Li Immunity The transcription factor PU.1 plays multiple context and concentration dependent roles in lymphoid and myeloid cell development. Here we showed that PU.1 (encoded by Sfpi1) was essential for dendritic cell (DC) development in vivo and that conditional ablation of PU.1 in defined precursors, including the common DC progenitor, blocked Flt3 ligand-induced DC generation in vitro. PU.1 was also required for the parallel granulocyte-macrophage colony stimulating factor-induced DC pathway from early hematopoietic progenitors. Molecular studies demonstrated that PU.1 directly regulated Flt3 in a concentration-dependent manner, as Sfpi1(+/-) cells displayed reduced expression of Flt3 and impaired DC formation. These studies identify PU.1 as a critical regulator of both conventional and plasmacytoid DC development and provide one mechanism how altered PU.1 concentration can have profound functional consequences for hematopoietic cell development. 10.1016/j.immuni.2010.05.005
    Histone Demethylase JMJD2D Interacts With β-Catenin to Induce Transcription and Activate Colorectal Cancer Cell Proliferation and Tumor Growth in Mice. Peng Kesong,Kou Lele,Yu Li,Bai Chaonan,Li Ming,Mo Pingli,Li Wengang,Yu Chundong Gastroenterology BACKGROUND & AIMS:Wnt signaling contributes to the development of colorectal cancer (CRC). We studied interactions between lysine demethylase 4D (KDM4D or JMJD2D) and β-catenin, a mediator of Wnt signaling, in CRC cell lines and the effects on tumor formation in mice. METHODS:We obtained colorectal tumor specimens and surrounding nontumor colon tissues (controls) from patients undergoing surgery in China; levels of JMJD2D were measured by immunohistochemical or immunoblot analysis. JMJD2D expression was knocked down in CRC (CT26, HCT116, and SW480 cells) using small hairpin RNAs, and cells were analyzed with viability, flow cytometry, colony formation, and transwell migration and invasion assays. Cells were also grown as tumor xenografts in nude mice or injected into tail veins or spleens of mice, and metastases were measured. We performed promoter activity, co-immunoprecipitation, and chromatin immunoprecipitation assays. We also performed studies with Apc and JMJD2D-knockout mice; these mice were crossed, and colorectal tumor formation in offspring (ApcJmjd2d and ApcJmjd2d) was analyzed. JMJD2D-knockout and wild-type (control) mice were given azoxymethane followed by dextran sodium sulfate to induce colitis-associated CRC; some mice were given the JMJD2D inhibitor 5-chloro-8-hydroxyquinoline (5-c-8HQ) or vehicle to examine the effects of 5-c-8HQ on intestinal tumor formation. RESULTS:Levels of JMJD2D were significantly higher in human colorectal tumors than in control tissues and correlated with levels of proliferating cell nuclear antigen. JMJD2D knockdown reduced CRC cell proliferation, migration, and invasion, as well as growth of xenograft tumors and formation of metastases in mice. JMJD2D was required for expression of β-catenin in CRC cell lines; ectopic expression of JMJD2D increased the promoter activities of genes regulated by β-catenin (MYC, CCND1, MMP2, and MMP9). We found that JMJD2D and β-catenin interacted physically and that JMJD2D demethylated H3K9me3 at promoters of β-catenin target genes. JMJD2D-knockout mice developed fewer colitis-associated colorectal tumors than control mice, and their tumor tissues had lower levels of β-catenin, MYC, cyclin D1, and proliferating cell nuclear antigen than tumors from control mice. ApcJmjd2d mice developed fewer and smaller colon tumors than Apc mice. Mice given 5-c-8HQ developed smaller and fewer colitis-associated tumors, with lower levels of cell proliferation, than mice given vehicle. Apc mice given 5-c-8HQ also developed fewer tumors in intestines and colons than mice given vehicle. CONCLUSIONS:Levels of the histone demethylase JMJD2D are increased in human colorectal tumors compared with nontumor colon tissues. JMJD2D interacts with β-catenin to activate transcription of its target genes and promote CRC cell proliferation, migration, and invasion, as well as formation of colorectal tumors in mice. 10.1053/j.gastro.2018.11.036
    Matrix metalloproteinase-9 might affect adaptive immunity in non-ST segment elevation acute coronary syndromes by increasing CD31 cleavage on CD4+ T-cells. Angelini Giulia,Flego Davide,Vinci Ramona,Pedicino Daniela,Trotta Francesco,Ruggio Aureliano,Piemontese Giuseppe P,Galante Domenico,Ponzo Myriana,Biasucci Luigi M,Liuzzo Giovanna,Crea Filippo European heart journal Aims:In patients with acute coronary syndrome (ACS), the higher activity of effector T-cells suggests that mechanisms involving adaptive immunity dysregulation might play a role in coronary instability. The shedding of the functional CD31 domain 1-5 leads to uncontrolled lymphocyte activation. In experimental models, matrix metalloproteinase-9 (MMP-9) has been implicated in endothelial CD31 cleavage. Interestingly, higher serum levels of MMP-9 have been observed in ACS. We aim to investigate the mechanisms underlying CD31 dysregulation in ACS. Methods and results:To assess CD31 cleavage on CD4+ T-cells, we analysed by flow cytometry CD4+ T-cells of 30 ACS, 25 stable angina (SA) patients, and 28 controls (CTRL) using two different CD31 antibodies that specifically recognize domain 1-5 or the non-functional membrane-proximal domain 6. The ratio between the domains was significantly lower in ACS than in SA and CTRL (P = 0.002 ACS vs. SA; P = 0.002 ACS vs. CTRL). After stimulation with anti-CD3/CD28, the 1-5/6 domain ratio was significantly lower in ACS than in SA (P = 0.005). ELISA of supernatants obtained from T-cell receptor-stimulated CD4+ T-cells showed higher production of MMP-9 in ACS than in SA (P < 0.001). CD31 domain 1-5 expression in activated CD4+ T-cells from ACS patients increased after treatment with a specific MMP-9 inhibitor (P = 0.042). Conclusion:Our study suggest that enhanced MMP-9 release plays a key role in determining the cleavage and shedding of the functional CD31 domain 1-5 in CD4+ T-cells of ACS patients. This mechanism might represent an important therapeutic target to modulate T-cell dysregulation in ACS. 10.1093/eurheartj/ehx684
    Human immunodeficiency virus-1 inhibition of immunoamphisomes in dendritic cells impairs early innate and adaptive immune responses. Blanchet Fabien P,Moris Arnaud,Nikolic Damjan S,Lehmann Martin,Cardinaud Sylvain,Stalder Romaine,Garcia Eduardo,Dinkins Christina,Leuba Florence,Wu Li,Schwartz Olivier,Deretic Vojo,Piguet Vincent Immunity Dendritic cells (DCs) in mucosal surfaces are early targets for human immunodeficiency virus-1 (HIV-1). DCs mount rapid and robust immune responses upon pathogen encounter. However, immune response in the early events of HIV-1 transmission appears limited, suggesting that HIV-1 evade early immune control by DCs. We report that HIV-1 induces a rapid shutdown of autophagy and immunoamphisomes in DCs. HIV-1 envelope activated the mammalian target of rapamycin pathway in DCs, leading to autophagy exhaustion. HIV-1-induced inhibition of autophagy in DC increased cell-associated HIV-1 and transfer of HIV-1 infection to CD4(+) T cells. HIV-1-mediated downregulation of autophagy in DCs impaired innate and adaptive immune responses. Immunoamphisomes in DCs engulf incoming pathogens and appear to amplify pathogen degradation as well as Toll-like receptor responses and antigen presentation. The findings that HIV-1 downregulates autophagy and impedes immune functions of DCs represent a pathogenesis mechanism that can be pharmacologically countered with therapeutic and prophylactic implications. 10.1016/j.immuni.2010.04.011
    Epigenetic instability of cytokine and transcription factor gene loci underlies plasticity of the T helper 17 cell lineage. Mukasa Ryuta,Balasubramani Anand,Lee Yun Kyung,Whitley Sarah K,Weaver Benjamin T,Shibata Yoichiro,Crawford Gregory E,Hatton Robin D,Weaver Casey T Immunity Phenotypic plasticity of T helper 17 (Th17) cells suggests instability of chromatin structure of key genes of this lineage. We identified epigenetic modifications across the clustered Il17a and Il17f and the Ifng loci before and after differential IL-12 or TGF-beta cytokine signaling, which induce divergent fates of Th17 cell precursors. We found that Th17 cell precursors had substantial remodeling of the Ifng locus, but underwent critical additional modifications to enable high expression when stimulated by IL-12. Permissive modifications across the Il17a-Il17f locus were amplified by TGF-beta signaling in Th17 cells, but were rapidly reversed downstream of IL-12-induced silencing of the Rorc gene by the transcription factors STAT4 and T-bet. These findings reveal substantial chromatin instability of key transcription factor and cytokine genes of Th17 cells and support a model of Th17 cell lineage plasticity in which cell-extrinsic factors modulate Th17 cell fates through differential effects on the epigenetic status of Th17 cell lineage factors. 10.1016/j.immuni.2010.04.016
    The association of cigarette smoking with enhanced platelet inhibition by clopidogrel. Bliden Kevin P,Dichiara Joseph,Lawal Lookman,Singla Anand,Antonino Mark J,Baker Brian A,Bailey William L,Tantry Udaya S,Gurbel Paul A Journal of the American College of Cardiology OBJECTIVES:The purpose of this study was to examine the effect of cigarette smoking on the platelet response to clopidogrel. BACKGROUND:Response variability to clopidogrel therapy has been demonstrated. Clopidogrel is metabolically activated by several hepatic cytochrome P450 (CYP) isoenzymes, including CYP1A2. Cigarette smoking induces CYP1A2 and may, therefore, enhance the conversion of clopidogrel to its active metabolite. METHODS:Among 259 consecutive patients undergoing elective coronary stenting; 120 were on chronic clopidogrel therapy and were not loaded; and 139 were clopidogrel naïve and were loaded with 600 mg. There were 104 current smokers (CS) and 155 nonsmokers (NS). The adenosine diphosphate (ADP)-stimulated platelet aggregation (PA) was assessed by conventional aggregometry. The ADP-stimulated total and active glycoprotein (GP) IIb/IIIa expression were assessed with flow cytometry. Low PA was defined as the lowest quartile of 5 micromol/l ADP-induced post-treatment PA. RESULTS:Current smokers on chronic clopidogrel therapy displayed significantly lower PA and ADP-stimulated active GP IIb/IIIa expression compared with NS (p < or = 0.0008 for both). Similarly, CS treated with 600 mg of clopidogrel displayed greater platelet inhibition and lower active GP IIb/IIIa expression compared with NS (p < or = 0.05). In a multivariate Cox regression analysis, current smoking was an independent predictor of low PA (p = 0.0001). CONCLUSION:Clopidogrel therapy in CS is associated with increased platelet inhibition and lower aggregation as compared with NS. The mechanism of the smoking effect deserves further study and may be an important cause of response variability to clopidogrel therapy. 10.1016/j.jacc.2008.04.045
    Role of reticulated platelets and platelet size heterogeneity on platelet activity after dual antiplatelet therapy with aspirin and clopidogrel in patients with stable coronary artery disease. Guthikonda Sasidhar,Alviar Carlos L,Vaduganathan Muthiah,Arikan Mehmet,Tellez Armando,DeLao Timothy,Granada Juan F,Dong Jing-Fei,Kleiman Neal S,Lev Eli I Journal of the American College of Cardiology OBJECTIVES:The aim of this study was to evaluate the relationship between reticulated platelets (RPs), platelet size, and platelet function in patients with stable coronary artery disease (CAD) taking aspirin and clopidogrel. BACKGROUND:Reticulated platelets are young platelets that are larger and possibly more active than non-RPs. METHODS:Flow cytometry was used to measure RPs after staining with thiazole orange and to define the upper 20% and lower 20% of platelets by size. Platelet aggregation was measured with light transmission aggregometry (LTA); platelet activation was assessed by measuring activated platelet surface expression of P-selectin and glycoprotein (GP) IIb/IIIa. RESULTS:Ninety patients were recruited and stratified into tertiles of %RPs. Patients in the upper tertile displayed greater platelet aggregation to 5-mumol/l adenosine diphosphate (ADP) (50.7 +/- 16.4% vs. 34.2 +/- 17.3%, p < 0.001), 1.5-mmol/l arachidonic acid (AA) (27.3 +/- 16.9% vs. 11.7 +/- 9.3%, p < 0.001), and 1-mug/ml collagen (18 +/- 11.6% vs. 12.1 +/- 8.7%, p < 0.05) and greater expression of GP IIb/IIIa (4.7 +/- 1.8% vs. 3.1 +/- 2.2%, p < 0.001). Frequency of low response to aspirin (AA LTA >20%) was higher in the upper tertile (53% vs. 17%, p < 0.001) compared with the lower tertile; low response to clopidogrel (ADP LTA >50%) was also elevated in the upper tertile (50% vs. 13%, p = 0.003). The larger platelet gate had a higher % of RPs compared with the smaller gate (15.4 +/- 16.7% vs. 1.7 +/- 2.3%, p < 0.001) and greater GP IIb/IIIa (5.7 +/- 3.1 vs. 2.1 +/- 1.2, p < 0.001) and P-selectin expression (7.8 +/- 4.9 vs. 4.6 +/- 2.7, p < 0.001). CONCLUSIONS:The proportion of circulating RPs strongly correlates with response to antiplatelet therapy in patients with stable CAD. Large platelets exhibit increased reactivity despite dual antiplatelet therapy, compared with smaller platelets. 10.1016/j.jacc.2008.05.031
    International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma. Kumar Shaji,Paiva Bruno,Anderson Kenneth C,Durie Brian,Landgren Ola,Moreau Philippe,Munshi Nikhil,Lonial Sagar,Bladé Joan,Mateos Maria-Victoria,Dimopoulos Meletios,Kastritis Efstathios,Boccadoro Mario,Orlowski Robert,Goldschmidt Hartmut,Spencer Andrew,Hou Jian,Chng Wee Joo,Usmani Saad Z,Zamagni Elena,Shimizu Kazuyuki,Jagannath Sundar,Johnsen Hans E,Terpos Evangelos,Reiman Anthony,Kyle Robert A,Sonneveld Pieter,Richardson Paul G,McCarthy Philip,Ludwig Heinz,Chen Wenming,Cavo Michele,Harousseau Jean-Luc,Lentzsch Suzanne,Hillengass Jens,Palumbo Antonio,Orfao Alberto,Rajkumar S Vincent,Miguel Jesus San,Avet-Loiseau Herve The Lancet. Oncology Treatment of multiple myeloma has substantially changed over the past decade with the introduction of several classes of new effective drugs that have greatly improved the rates and depth of response. Response criteria in multiple myeloma were developed to use serum and urine assessment of monoclonal proteins and bone marrow assessment (which is relatively insensitive). Given the high rates of complete response seen in patients with multiple myeloma with new treatment approaches, new response categories need to be defined that can identify responses that are deeper than those conventionally defined as complete response. Recent attempts have focused on the identification of residual tumour cells in the bone marrow using flow cytometry or gene sequencing. Furthermore, sensitive imaging techniques can be used to detect the presence of residual disease outside of the bone marrow. Combining these new methods, the International Myeloma Working Group has defined new response categories of minimal residual disease negativity, with or without imaging-based absence of extramedullary disease, to allow uniform reporting within and outside clinical trials. In this Review, we clarify several aspects of disease response assessment, along with endpoints for clinical trials, and highlight future directions for disease response assessments. 10.1016/S1470-2045(16)30206-6
    An Slfn2 mutation causes lymphoid and myeloid immunodeficiency due to loss of immune cell quiescence. Berger Michael,Krebs Philippe,Crozat Karine,Li Xiaohong,Croker Ben A,Siggs Owen M,Popkin Daniel,Du Xin,Lawson Brian R,Theofilopoulos Argyrios N,Xia Yu,Khovananth Kevin,Moresco Eva Marie,Satoh Takashi,Takeuchi Osamu,Akira Shizuo,Beutler Bruce Nature immunology Here we describe a previously unknown form of inherited immunodeficiency revealed by an N-ethyl-N-nitrosourea-induced mutation called elektra. Mice homozygous for this mutation showed enhanced susceptibility to bacterial and viral infection and diminished numbers of T cells and inflammatory monocytes that failed to proliferate after infection and died via the intrinsic apoptotic pathway in response to diverse proliferative stimuli. They also had a greater proportion of T cells poised to replicate DNA, and their T cells expressed a subset of activation markers, suggestive of a semi-activated state. We positionally ascribe the elektra phenotype to a mutation in the gene encoding Schlafen-2 (Slfn2). Our findings identify a physiological role for Slfn2 in the defense against pathogens through the regulation of quiescence in T cells and monocytes. 10.1038/ni.1847
    Notch dimerization is required for leukemogenesis and T-cell development. Liu Hudan,Chi Anthony W S,Arnett Kelly L,Chiang Mark Y,Xu Lanwei,Shestova Olga,Wang Hongfang,Li Yue-Ming,Bhandoola Avinash,Aster Jon C,Blacklow Stephen C,Pear Warren S Genes & development Notch signaling regulates myriad cellular functions by activating transcription, yet how Notch selectively activates different transcriptional targets is poorly understood. The core Notch transcriptional activation complex can bind DNA as a monomer, but it can also dimerize on DNA-binding sites that are properly oriented and spaced. However, the significance of Notch dimerization is unknown. Here, we show that dimeric Notch transcriptional complexes are required for T-cell maturation and leukemic transformation but are dispensable for T-cell fate specification from a multipotential precursor. The varying requirements for Notch dimerization result from the differential sensitivity of specific Notch target genes. In particular, c-Myc and pre-T-cell antigen receptor α (Ptcra) are dimerization-dependent targets, whereas Hey1 and CD25 are not. These findings identify functionally important differences in the responsiveness among Notch target genes attributable to the formation of higher-order complexes. Consequently, it may be possible to develop a new class of Notch inhibitors that selectively block outcomes that depend on Notch dimerization (e.g., leukemogenesis). 10.1101/gad.1975210
    HBV inhibits LPS-induced NLRP3 inflammasome activation and IL-1β production via suppressing the NF-κB pathway and ROS production. Yu Xin,Lan Peixiang,Hou Xuben,Han Qiuju,Lu Nan,Li Tao,Jiao Chenwei,Zhang Jian,Zhang Cai,Tian Zhigang Journal of hepatology BACKGROUND & AIMS:Hepatitis B virus (HBV) has developed strategies to evade immune responses. However, the mechanisms involved remain unclear. The NLRP3 inflammasome plays crucial roles in antiviral host defense and its downstream factor IL-1β has been shown to inhibit HBV infection in vivo. This study aims to assess whether HBV can affect the NLRP3 inflammasome signaling pathways and shed light on the underlying mechanisms HBV utilizes to evade host innate immune responses. METHODS:HBV inhibition of the lipopolysaccharide (LPS)-induced NLRP3 inflammasome activation was evaluated by Western blot, quantitative RT-PCR, flow cytometry and immunofluorescence. RESULTS:Kupffer cells expressed significantly more NLRP3 and IL-1β after LPS stimulation; whereas, chronic HBV infection suppressed LPS-induced NLRP3 and pro-IL-1β expression as well as IL-1β maturation. This inhibitory activity is mediated by HBeAg, and is involved in the inhibition of NF-κB signal pathway and reactive oxygen species (ROS) production. The inhibitory effect of HBeAg was confirmed in patients with chronic hepatitis B (CHB) and hepatocellular carcinoma by comparing the levels of IL-1β and NLRP3-related proteins in para-carcinoma tissues from HBeAg-positive or negative patients. Moreover, chronic HBV infection increases the susceptibility of mice to S. typhimurium infection, possibly via inhibiting the NLRP3 inflammasome activation and IL-1β production. CONCLUSIONS:HBeAg inhibits LPS-induced NLRP3 inflammasome activation and IL-1β production via suppressing NF-κB pathway and ROS production. This finding provides a novel mechanism for HBV-mediated suppression of innate immune responses, and identifies new therapeutic targets for chronic HBV infection and related diseases. LAY SUMMARY:HBeAg suppresses LPS-induced NLRP3 inflammasome activation and IL-1β production in two ways, one is to repress NLRP3 and pro-IL-1β expression via inhibiting NF-κB phosphorylation, and the other is to repress caspase-1 activation and IL-1β maturation via inhibiting ROS production. This effect contributes to the HBV persistence and immune tolerance. 10.1016/j.jhep.2016.12.018
    Predicting and managing primary and secondary non-response to rituximab using B-cell biomarkers in systemic lupus erythematosus. Md Yusof Md Yuzaiful,Shaw Daniel,El-Sherbiny Yasser M,Dunn Emma,Rawstron Andy C,Emery Paul,Vital Edward M Annals of the rheumatic diseases OBJECTIVE:To assess factors associated with primary and secondary non-response to rituximab in systemic lupus erythematosus (SLE) and evaluate management of secondary non-depletion non-response (2NDNR). METHODS:125 patients with SLE treated with rituximab over 12 years were studied prospectively. A major clinical response was defined as improvement of all active British Isles Lupus Assessment Group (BILAG)-2004 domains to grade C/better and no A/B flare. Partial responders were defined by one persistent BILAG B. B-cell subsets were measured using highly sensitive flow cytometry. Patients with 2NDNR, defined by infusion reaction and defective depletion, were treated with ocrelizumab or ofatumumab. RESULTS:117 patients had evaluable data. In cycle 1 (C1), 96/117 (82%) achieved BILAG response (major=50%, partial=32%). In multivariable analysis, younger age (OR 0.97, 95% CI 0.94 to 1.00) and B-cell depletion at 6 weeks (OR 3.22, 95% CI 1.24 to 8.33) increased the odds of major response. Complete depletion was predicted by normal complement and lower pre-rituximab plasmablasts and was not associated with increased serious infection post-rituximab. Seventy-seven (with data on 72) C1 responders were retreated on clinical relapse. Of these, 61/72 (85%) responded in cycle 2 (C2). Of the 11 C2 non-responders, nine met 2NDNR criteria (incidence=12%) and tested positive for anti-rituximab antibodies. Lack of concomitant immunosuppressant and higher pre-rituximab plasmablasts predicted 2NDNR. Five were switched to ocrelizumab/ofatumumab, and all depleted and responded. CONCLUSION:Treatment with anti-CD20 agents can be guided by B-cell monitoring and should aim to achieve complete depletion. 2NDNR is associated with anti-rituximab antibodies, and switching to humanised agents restores depletion and response. In SLE, alternative anti-CD20 antibodies may be more consistently effective. 10.1136/annrheumdis-2017-211191
    Alternative cross-priming through CCL17-CCR4-mediated attraction of CTLs toward NKT cell-licensed DCs. Semmling Verena,Lukacs-Kornek Veronika,Thaiss Christoph A,Quast Thomas,Hochheiser Katharina,Panzer Ulf,Rossjohn Jamie,Perlmutter Patrick,Cao Jia,Godfrey Dale I,Savage Paul B,Knolle Percy A,Kolanus Waldemar,Förster Irmgard,Kurts Christian Nature immunology Cross-priming allows dendritic cells (DCs) to induce cytotoxic T cell (CTL) responses to extracellular antigens. DCs require cognate 'licensing' for cross-priming, classically by helper T cells. Here we demonstrate an alternative mechanism for cognate licensing by natural killer T (NKT) cells recognizing microbial or synthetic glycolipid antigens. Such licensing caused cross-priming CD8alpha(+) DCs to produce the chemokine CCL17, which attracted naive CTLs expressing the chemokine receptor CCR4. In contrast, DCs licensed by helper T cells recruited CTLs using CCR5 ligands. Thus, depending on the type of antigen they encounter, DCs can be licensed for cross-priming by NKT cells or helper T cells and use at least two independent chemokine pathways to attract naive CTLs. Because these chemokines acted synergistically, this can potentially be exploited to improve vaccinations. 10.1038/ni.1848
    Regulation of leukocyte recruitment by the long pentraxin PTX3. Deban Livija,Russo Remo Castro,Sironi Marina,Moalli Federica,Scanziani Margherita,Zambelli Vanessa,Cuccovillo Ivan,Bastone Antonio,Gobbi Marco,Valentino Sonia,Doni Andrea,Garlanda Cecilia,Danese Silvio,Salvatori Giovanni,Sassano Marica,Evangelista Virgilio,Rossi Barbara,Zenaro Elena,Constantin Gabriela,Laudanna Carlo,Bottazzi Barbara,Mantovani Alberto Nature immunology Pentraxins are a superfamily of conserved proteins involved in the acute-phase response and innate immunity. Pentraxin 3 (PTX3), a prototypical member of the long pentraxin subfamily, is a key component of the humoral arm of innate immunity that is essential for resistance to certain pathogens. A regulatory role for pentraxins in inflammation has long been recognized, but the underlying mechanisms remain unclear. Here we report that PTX3 bound P-selectin and attenuated neutrophil recruitment at sites of inflammation. PTX3 released from activated leukocytes functioned locally to dampen neutrophil recruitment and regulate inflammation. Antibodies have glycosylation-dependent regulatory effect on inflammation. Therefore, PTX3, which is an essential component of humoral innate immunity, and immunoglobulins share functional outputs, including complement activation, opsonization and, as shown here, glycosylation-dependent regulation of inflammation. 10.1038/ni.1854
    CD169(+) macrophages present lipid antigens to mediate early activation of iNKT cells in lymph nodes. Barral Patricia,Polzella Paolo,Bruckbauer Andreas,van Rooijen Nico,Besra Gurdyal S,Cerundolo Vincenzo,Batista Facundo D Nature immunology Invariant natural killer T cells (iNKT cells) are involved in the host defense against microbial infection. Although it is known that iNKT cells recognize glycolipids presented by CD1d, how and where they encounter antigen in vivo remains unclear. Here we used multiphoton microscopy to visualize the dynamics and activation of iNKT cells in lymph nodes. After antigen administration, iNKT cells became confined in a CD1d-dependent manner in close proximity to subcapsular sinus CD169(+) macrophages. These macrophages retained, internalized and presented lipid antigen and were required for iNKT cell activation, cytokine production and population expansion. Thus, CD169(+) macrophages can act as true antigen-presenting cells controlling early iNKT cell activation and favoring the fast initiation of immune responses. 10.1038/ni.1853
    Haematopoietic stem cells derive directly from aortic endothelium during development. Bertrand Julien Y,Chi Neil C,Santoso Buyung,Teng Shutian,Stainier Didier Y R,Traver David Nature A major goal of regenerative medicine is to instruct formation of multipotent, tissue-specific stem cells from induced pluripotent stem cells (iPSCs) for cell replacement therapies. Generation of haematopoietic stem cells (HSCs) from iPSCs or embryonic stem cells (ESCs) is not currently possible, however, necessitating a better understanding of how HSCs normally arise during embryonic development. We previously showed that haematopoiesis occurs through four distinct waves during zebrafish development, with HSCs arising in the final wave in close association with the dorsal aorta. Recent reports have suggested that murine HSCs derive from haemogenic endothelial cells (ECs) lining the aortic floor. Additional in vitro studies have similarly indicated that the haematopoietic progeny of ESCs arise through intermediates with endothelial potential. Here we have used the unique strengths of the zebrafish embryo to image directly the generation of HSCs from the ventral wall of the dorsal aorta. Using combinations of fluorescent reporter transgenes, confocal time-lapse microscopy and flow cytometry, we have identified and isolated the stepwise intermediates as aortic haemogenic endothelium transitions to nascent HSCs. Finally, using a permanent lineage tracing strategy, we demonstrate that the HSCs generated from haemogenic endothelium are the lineal founders of the adult haematopoietic system. 10.1038/nature08738
    B-cell clones as early markers for chronic lymphocytic leukemia. Landgren Ola,Albitar Maher,Ma Wanlong,Abbasi Fatima,Hayes Richard B,Ghia Paolo,Marti Gerald E,Caporaso Neil E The New England journal of medicine BACKGROUND:Otherwise healthy persons with a small number of B-cell clones circulating in the peripheral blood have been designated as having monoclonal B-cell lymphocytosis (MBL). Hospital-based series indicate an excess risk of progression from MBL to chronic lymphocytic leukemia (CLL). In this prospective cohort study, we tested the hypothesis that CLL is always preceded by MBL. METHODS:Among 77,469 healthy adults who were enrolled in the nationwide, population-based Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, we identified 45 subjects in whom CLL was subsequently diagnosed (up to 6.4 years later) through the collection of a peripheral-blood sample. Using six-color flow cytometry (with antibodies CD45, CD19, CD5, CD10, kappa, and lambda) and immunoglobulin heavy-chain gene rearrangement by reverse-transcriptase-polymerase-chain-reaction assay, we determined the association between MBL and subsequent CLL and characterized the immunoglobulin gene repertoire of the prediagnostic B-cell clones. RESULTS:On the basis of either flow-cytometric or molecular analysis, 44 of 45 patients with CLL (98%; 95% confidence interval [CI], 88 to 100) had a prediagnostic B-cell clone; in 41 patients (91%; 95% CI, 79 to 98), the presence of the B-cell clone was confirmed by both methods. The presence of immunoglobulin heavy-chain variable (IGHV) genes was determined in 35 of 45 prediagnostic clones (78%). Of these clones, 16 (46%) were IGHV3 subgroup genes (including 6 [17%] IGHV3-23 genes) and 9 (26%) were IGHV4 subgroup genes (including 4 [11%] IGHV4-34 genes). Furthermore, 27 of 35 of the IGHV sequences (77%) had mutations, with similar distributions after stratification either below or above the median time between the collection of the prediagnostic blood sample and the subsequent CLL diagnosis. CONCLUSIONS:In peripheral blood obtained up to 77 months before a CLL diagnosis, prediagnostic B-cell clones were present in 44 of 45 patients with CLL. 10.1056/NEJMoa0806122
    Delayed neutrophil apoptosis in patients with sleep apnea. Dyugovskaya Larissa,Polyakov Andrey,Lavie Peretz,Lavie Lena American journal of respiratory and critical care medicine RATIONALE:Obstructive sleep apnea (OSA), characterized by intermittent hypoxia/reoxygenation (IHR), is associated with atherosclerosis. Polymorphonuclear leukocytes (PMNs) are implicated in atherogenesis by producing oxidizing radicals and proteolytic enzymes during PMN-endothelium interactions. PMN apoptosis is a fundamental, injury-limiting mechanism, which prevents their destructive potential. OBJECTIVES:To determine whether PMN apoptosis and expression of adhesion molecules are affected by OSA and IHR in vitro. METHODS:Apoptosis and expression of adhesion molecules were assessed in whole blood PMNs by flow cytometry, verified by various culture conditions, and morphology. These were complemented by exposing whole blood and purified PMNs to IHR and to sustained hypoxia in vitro. MEASUREMENTS AND MAIN RESULTS:This study demonstrates for the first time that, in patients with moderate to severe OSA, PMN apoptosis is delayed. Apoptosis was attenuated in patients with an apnea-hypopnea index (AHI) of more than 15, determined by decreased expression of low-CD16/annexin-V-positive PMNs, by lowered caspase-3 activity and nuclear condensation. Concomitantly, selectin-CD15 expression was increased in a severity-dependent manner in patients with moderate to severe OSA having an AHI greater than 15. The percentage of apoptotic PMNs was negatively correlated with OSA severity, determined by AHI, and positively with CD15 expression. In nasal continuous positive airway pressure-treated patients, CD15 expression was attenuated and low CD16 was increased, whereas omitting nasal continuous positive airway pressure for a single night increased CD15 expression and decreased the percentage of low CD16. IHR in vitro delayed PMN apoptosis as well. CONCLUSIONS:Decreased apoptosis and increased expression of adhesion molecules were noted in OSA PMNs. Although adhesion molecules may facilitate increased PMN-endothelium interactions, decreased apoptosis may further augment these interactions and facilitate free radical and proteolytic enzyme release. 10.1164/rccm.200705-675OC
    Flow cytometry as a predictive indicator in patients with operable gastric cancer. Nanus D M,Kelsen D P,Niedzwiecki D,Chapman D,Brennan M,Cheng E,Melamed M Journal of clinical oncology : official journal of the American Society of Clinical Oncology Adenocarcinoma of the proximal portion of the stomach (gastroesophageal [GE] junction and cardia) is increasing in incidence. The inferior survival of patients with GE-cardia lesions as compared with patients with tumors located in the body and antrum has been attributed to anatomic features. To determine if a biological difference could explain the varying prognosis, flow cytometric studies were performed prospectively in 50 patients with operable gastric cancer and analyzed for association with site, histology, gender, age, stage, and disease-free survival. DNA aneuploidy significantly correlated with tumor location: 96% of GE-cardia carcinomas were aneuploid as compared with 48% of body-antrum tumors (P = .0008). Nodal involvement was more common in aneuploid tumors (P = .0548), and women were more likely to have diploid tumors than were men (P = .0233). The median disease-free survival for patients with diploid tumors was 18.5 months as compared with 5.4 months for patients with aneuploid carcinomas (P = .076). Furthermore, within the body-antrum of the stomach, patients with diploid tumors had a significantly better disease-free survival than did those with aneuploid tumors from the same site (18.4 v 4.7 months, P = .0185). These results indicate there is a difference in the DNA content of gastric tumors located in different sites within the stomach and that DNA content correlates with prognosis. 10.1200/JCO.1989.7.8.1105
    Plasma Cells Are the Most Abundant Gluten Peptide MHC-expressing Cells in Inflamed Intestinal Tissues From Patients With Celiac Disease. Høydahl Lene Støkken,Richter Lisa,Frick Rahel,Snir Omri,Gunnarsen Kristin Støen,Landsverk Ole J B,Iversen Rasmus,Jeliazkov Jeliazko R,Gray Jeffrey J,Bergseng Elin,Foss Stian,Qiao Shuo-Wang,Lundin Knut E A,Jahnsen Jørgen,Jahnsen Frode L,Sandlie Inger,Sollid Ludvig M,Løset Geir Åge Gastroenterology BACKGROUND & AIMS:Development of celiac disease is believed to involve the transglutaminase-dependent response of CD4 T cells toward deamidated gluten peptides in the intestinal mucosa of individuals with specific HLA-DQ haplotypes. We investigated the antigen presentation process during this mucosal immune response. METHODS:We generated monoclonal antibodies (mAbs) specific for the peptide-MHC (pMHC) complex of HLA-DQ2.5 and the immunodominant gluten epitope DQ2.5-glia-α1a using phage display. We used these mAbs to assess gluten peptide presentation and phenotypes of presenting cells by flow cytometry and enzyme-linked immune absorbent spot (ELISPOT) in freshly prepared single-cell suspensions from intestinal biopsies from 40 patients with celiac disease (35 untreated and 5 on a gluten-free diet) as well as 18 subjects with confirmed noninflamed gut mucosa (controls, 12 presumed healthy, 5 undergoing pancreatoduodenectomy, and 1 with potential celiac disease). RESULTS:Using the mAbs, we detected MHC complexes on cells from intestinal biopsies from patients with celiac disease who consume gluten, but not from patients on gluten-free diets. We found B cells and plasma cells to be the most abundant cells that present DQ2.5-glia-α1a in the inflamed mucosa. We identified a subset of plasma cells that expresses B-cell receptors (BCR) specific for gluten peptides or the autoantigen transglutaminase 2 (TG2). Expression of MHC class II (MHCII) was not restricted to these specific plasma cells in patients with celiac disease but was observed in an average 30% of gut plasma cells from patients and controls. CONCLUSIONS:A population of plasma cells from intestinal biopsies of patients with celiac disease express MHCII; this is the most abundant cell type presenting the immunodominant gluten peptide DQ2.5-glia-α1a in the tissues from these patients. These results indicate that plasma cells in the gut can function as antigen-presenting cells and might promote and maintain intestinal inflammation in patients with celiac disease or other inflammatory disorders. 10.1053/j.gastro.2018.12.013
    DNA modification of live cell surface. Borisenko Grigory G,Zaitseva Marina A,Chuvilin Andrey N,Pozmogova Galina E Nucleic acids research We report a novel approach for the attachment of DNA fragments to the surface of live cells. By using fluorescence microscopy and flow cytometry we demonstrated that our synthetic conjugates of fatty acid with oligonucleotides can be incorporated in plasma membrane and then hybridized with complementary sequences at the cell surface. Method permits to control amount of immobilized DNA on the cell surface. All procedures can be completed within minutes and do not alter cell viability. Using this approach we tethered floating myeloid HL-60 cells to adherent A431 epitheliocytes in a sequence specific fashion. Thus, this method allows rapid and simple DNA multicoding of the cell surface and, therefore, opens new opportunities in manipulating with cell-cell interactions. 10.1093/nar/gkn1034
    Conserved antagonism between JMJD2A/KDM4A and HP1γ during cell cycle progression. Black Joshua C,Allen Andrew,Van Rechem Capucine,Forbes Emily,Longworth Michelle,Tschöp Katrin,Rinehart Claire,Quiton Jonathan,Walsh Ryan,Smallwood Andrea,Dyson Nicholas J,Whetstine Johnathan R Molecular cell The KDM4/JMJD2 family of histone demethylases is amplified in human cancers. However, little is known about their physiologic or tumorigenic roles. We have identified a conserved and unappreciated role for the JMJD2A/KDM4A H3K9/36 tridemethylase in cell cycle progression. We demonstrate that JMJD2A protein levels are regulated in a cell cycle-dependent manner and that JMJD2A overexpression increased chromatin accessibility, S phase progression, and altered replication timing of specific genomic loci. These phenotypes depended on JMJD2A enzymatic activity. Strikingly, depletion of the only C. elegans homolog, JMJD-2, slowed DNA replication and increased ATR/p53-dependent apoptosis. Importantly, overexpression of HP1γ antagonized JMJD2A-dependent progression through S phase, and depletion of HPL-2 rescued the DNA replication-related phenotypes in jmjd-2(-/-) animals. Our findings describe a highly conserved model whereby JMJD2A regulates DNA replication by antagonizing HP1γ and controlling chromatin accessibility. 10.1016/j.molcel.2010.11.008
    Intestinal microbes affect phenotypes and functions of invariant natural killer T cells in mice. Wingender Gerhard,Stepniak Dariusz,Krebs Philippe,Lin Lin,McBride Sara,Wei Bo,Braun Jonathan,Mazmanian Sarkis K,Kronenberg Mitchell Gastroenterology BACKGROUND & AIMS:Invariant natural killer T (iNKT) cells undergo canonical, Vα14-Jα18 rearrangement of the T-cell receptor (TCR) in mice; this form of the TCR recognizes glycolipids presented by CD1d. iNKT cells mediate many different immune reactions. Their constitutive activated and memory phenotype and rapid initiation of effector functions after stimulation indicate previous antigen-specific stimulation. However, little is known about this process. We investigated whether symbiotic microbes can determine the activated phenotype and function of iNKT cells. METHODS:We analyzed the numbers, phenotypes, and functions of iNKT cells in germ-free mice, germ-free mice reconstituted with specified bacteria, and mice housed in specific pathogen-free environments. RESULTS:Specific pathogen-free mice, obtained from different vendors, have different intestinal microbiota. iNKT cells isolated from these mice differed in TCR Vβ7 frequency and cytokine response to antigen, which depended on the environment. iNKT cells isolated from germ-free mice had a less mature phenotype and were hyporesponsive to activation with the antigen α-galactosylceramide. Intragastric exposure of germ-free mice to Sphingomonas bacteria, which carry iNKT cell antigens, fully established phenotypic maturity of iNKT cells. In contrast, reconstitution with Escherichia coli, which lack specific antigens for iNKT cells, did not affect the phenotype of iNKT cells. The effects of intestinal microbes on iNKT cell responsiveness did not require Toll-like receptor signals, which can activate iNKT cells independently of TCR stimulation. CONCLUSIONS:Intestinal microbes can affect iNKT cell phenotypes and functions in mice. 10.1053/j.gastro.2012.04.017
    Early fate of exogenous promoters in E. coli. Yousuf Malikmohamed,Iuliani Ilaria,Veetil Reshma T,Seshasayee Aswin Sai Narain,Sclavi Bianca,Cosentino Lagomarsino Marco Nucleic acids research Gene gain by horizontal gene transfer is a major pathway of genome innovation in bacteria. The current view posits that acquired genes initially need to be silenced and that a bacterial chromatin protein, H-NS, plays a role in this silencing. However, we lack direct observation of the early fate of a horizontally transferred gene to prove this theory. We combine sequencing, flow cytometry and sorting, followed by microscopy to monitor gene expression and its variability after large-scale random insertions of a reporter gene in a population of Escherichia coli bacteria. We find that inserted promoters have a wide range of gene-expression variability related to their location. We find that high-expression clones carry insertions that are not correlated with H-NS binding. Conversely, binding of H-NS correlates with silencing. Finally, while most promoters show a common level of extrinsic noise, some insertions show higher noise levels. Analysis of these high-noise clones supports a scenario of switching due to transcriptional interference from divergent ribosomal promoters. Altogether, our findings point to evolutionary pathways where newly-acquired genes are not necessarily silenced, but may immediately explore a wide range of expression levels to probe the optimal ones. 10.1093/nar/gkz1196
    Innate phagocytosis by peripheral blood monocytes is altered in Alzheimer's disease. Gu Ben J,Huang Xin,Ou Amber,Rembach Alan,Fowler Christopher,Avula Pavan K,Horton Adam,Doecke James D,Villemagne Victor L,Macaulay S Lance,Maruff Paul,Fletcher Erica L,Guymer Robyn,Wiley James S,Masters Colin L, Acta neuropathologica Sporadic Alzheimer's disease (AD) is characterised by the deposition and accumulation of specific protein aggregates. Failure of clearance could underlie this process, and recent genetic association studies point towards involvement of the phagocytosis and autophagy pathways. We developed a real-time tri-color flow cytometry method to quantitate the phagocytic function of human peripheral blood monocyte subsets including non-classic CD14(dim)CD16(+), intermediate CD14(+)CD16(+) and classic CD14(+)CD16(-) monocytes. Using this method, we have measured the phagocytic ability of fresh monocytes in a study of preclinical, prodromal and clinical AD, matched with cognitively normal healthy control subjects. Basal levels of phagocytosis in all three subsets of monocytes were similar between healthy controls and AD patients, while a significant increase of basal phagocytosis was found in subjects with high Aβ-amyloid burden as assessed by PET scans. Pre-treating cells with Copaxone (CPX, to stimulate phagocytosis) or ATP (an inhibitor of P2X7-mediated phagocytosis) showed a differential response depending on clinical or Aβ-burden status, indicating a relative functional deficit. Overall the results are consistent with a perturbation of basal and stimulated innate phagocytosis in sporadic AD. 10.1007/s00401-016-1596-3
    Systemic antibody responses to gut commensal bacteria during chronic HIV-1 infection. Haas Anna,Zimmermann Kathrin,Graw Frederik,Slack Emma,Rusert Peter,Ledergerber Bruno,Bossart Walter,Weber Rainer,Thurnheer Maria C,Battegay Manuel,Hirschel Bernard,Vernazza Pietro,Patuto Nicola,Macpherson Andrew J,Günthard Huldrych F,Oxenius Annette, Gut BACKGROUND:Human systemic antibody responses to commensal microbiota are not well characterised during health and disease. Of particular interest is the analysis of their potential modulation caused by chronic HIV-1 infection which is associated with sustained enteropathy and systemic B cell disturbances reflected by impaired B cell responses and chronic B cell hyperactivity. The mechanisms underlying B cell hyperactivation and the specificities of the resulting hypergammaglobulinaemia are only poorly understood. METHODS:By a technique referred to as live bacterial FACS (fluorescence-activated cell sorting), the present study investigated systemic antibody responses to several gut and skin commensal bacteria as well as Candida albicans in longitudinal plasma and serum samples from healthy donors, chronic HIV-1-infected individuals with or without diarrhoea and patients with inflammatory bowel disease (IBD). RESULTS:The data show that systemic antibody responses to the commensal microbiota were abundantly present in humans and remained remarkably stable over years. Overall systemic antibody responses to gut commensal bacteria were not affected during chronic HIV-1 infection, with titres decreasing when normalised to elevated plasma immunoglobulin G (IgG) levels found in patients with HIV. In contrast, increases in the titres of high affinity antimicrobiota antibodies were detected in patients with IBD, demonstrating that conditions with known increased intestinal permeability and aberrant mutualism can induce changes in antibody titres observed in these assays. CONCLUSION:Neither HIV-associated enteropathy nor B cell dysfunction impact on the high-affinity systemic antibody responses to gut commensal bacteria. HIV-associated hypergammaglobulinaemia is therefore unlikely to be driven by induction of antimicrobiota antibodies. 10.1136/gut.2010.224774
    Altered activation of endothelial anti- and proapoptotic pathways by high-density lipoprotein from patients with coronary artery disease: role of high-density lipoprotein-proteome remodeling. Riwanto Meliana,Rohrer Lucia,Roschitzki Bernd,Besler Christian,Mocharla Pavani,Mueller Maja,Perisa Damir,Heinrich Kathrin,Altwegg Lukas,von Eckardstein Arnold,Lüscher Thomas F,Landmesser Ulf Circulation BACKGROUND:Endothelial dysfunction and injury are thought to play an important role in the progression of coronary artery disease (CAD). High-density lipoprotein from healthy subjects (HDL(Healthy)) has been proposed to exert endothelial antiapoptotic effects that may represent an important antiatherogenic property of the lipoprotein. The present study therefore aimed to compare effects of HDL(CAD) and HDL(Healthy) on the activation of endothelial anti- and proapoptotic pathways and to determine which changes of the lipoprotein are relevant for these processes. METHODS AND RESULTS:HDL was isolated from patients with stable CAD (HDL(sCAD)), an acute coronary syndrome (HDL(ACS)), and healthy subjects. HDL(Healthy) induced expression of the endothelial antiapoptotic Bcl-2 protein Bcl-xL and reduced endothelial cell apoptosis in vitro and in apolipoprotein E-deficient mice in vivo. In contrast, HDL(sCAD) and HDL(ACS) did not inhibit endothelial apoptosis, failed to activate endothelial Bcl-xL, and stimulated endothelial proapoptotic pathways, in particular, p38-mitogen-activated protein kinase-mediated activation of the proapoptotic Bcl-2 protein tBid. Endothelial antiapoptotic effects of HDL(Healthy) were observed after inhibition of endothelial nitric oxide synthase and after delipidation, but not completely mimicked by apolipoprotein A-I or reconstituted HDL, suggesting an important role of the HDL proteome. HDL proteomics analyses and subsequent validations and functional characterizations suggested a reduced clusterin and increased apolipoprotein C-III content of HDL(sCAD) and HDL(ACS) as mechanisms leading to altered effects on endothelial apoptosis. CONCLUSIONS:The present study demonstrates for the first time that HDL(CAD) does not activate endothelial antiapoptotic pathways, but rather stimulates potential endothelial proapoptotic pathways. HDL-proteome remodeling plays an important role for these altered functional properties of HDL. These findings provide novel insights into mechanisms leading to altered vascular effects of HDL in coronary disease. 10.1161/CIRCULATIONAHA.112.108753
    Hepatocytes that express variants of cyclophilin A are resistant to HCV infection and replication. von Hahn Thomas,Schiene-Fischer Cordelia,Van Nguyen Dinh,Pfaender Stephanie,Karavul Behya,Steinmann Eike,Potthoff Andrej,Strassburg Christian,Hamdi Nabila,Abdelaziz Ahmed I,Sarrazin Christoph,Müller Tobias,Berg Thomas,Trépo Eric,Wedemeyer Heiner,Manns Michael P,Pietschmann Thomas,Ciesek Sandra Gastroenterology BACKGROUND & AIMS:Hepatitis C virus (HCV) uses several host factors to infect and replicate in human hepatocytes. Cyclophilin A (CypA) is required for viral replication, and CypA inhibitors are in development. We investigated the effects of nonsynonymous single nucleotide polymorphisms (SNPs) in the region of peptidyl-prolyl isomerase A (PPIA) that encodes CypA on HCV infection and replication of human hepatocytes. METHODS:We used a combination of virologic, biochemical, and genetic approaches to investigate the effects of PPIA variants on HCV replication in cultured Huh-7.5 cells. We reduced levels of CypA in these cells using small hairpin RNAs (shRNAs). RESULTS:Using shRNAs, we showed that CypA was required for replication of HCV in Huh-7.5 cells and identified 3 SNPs in PPIA that protected cells from HCV entry or replication. Levels of HCV RNA were reduced 3-4 log in cells homozygous for the variant alleles; release of new particles was also reduced, but viral entry was not affected. The effects of the variant alleles were recessive and stronger for preventing replication of full-length HCV genomes than subgenomes. CypA inhibitors prevented replication of residual HCV in hepatocytes. The variants appeared to destabilize the CypA protein; the single amino acid changes led to rapid degradation of the protein. CONCLUSIONS:We identified variants in PPIA that destabilize its product, CypA, and prevent HCV infection and replication. These findings indicate mechanisms by which some cells might be resistant to HCV infection and that CypA is a good therapeutic target. 10.1053/j.gastro.2012.04.053
    Tumor-induced tolerance and immune suppression depend on the C/EBPbeta transcription factor. Marigo Ilaria,Bosio Erika,Solito Samantha,Mesa Circe,Fernandez Audry,Dolcetti Luigi,Ugel Stefano,Sonda Nada,Bicciato Silvio,Falisi Erika,Calabrese Fiorella,Basso Giuseppe,Zanovello Paola,Cozzi Emanuele,Mandruzzato Susanna,Bronte Vincenzo Immunity Tumor growth is associated with a profound alteration in myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). We showed that among factors produced by various experimental tumors, the cytokines GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of CD8(+) T cells and allow long term acceptance of pancreatic islet allografts. Cytokines inducing MDSCs acted on a common molecular pathway and the immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on the C/EBPbeta transcription factor. Adoptive transfer of tumor antigen-specific CD8(+) T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBPbeta in the myeloid compartment, suggesting that C/EBPbeta is a critical regulator of the immunosuppressive environment created by growing cancers. 10.1016/j.immuni.2010.05.010
    Mammalian target of rapamycin protein complex 2 regulates differentiation of Th1 and Th2 cell subsets via distinct signaling pathways. Lee Keunwook,Gudapati Prathyusha,Dragovic Srdjan,Spencer Charles,Joyce Sebastian,Killeen Nigel,Magnuson Mark A,Boothby Mark Immunity Many functions of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) have been defined, but relatively little is known about the biology of an alternative mTOR complex, mTORC2. We showed that conditional deletion of rictor, an essential subunit of mTORC2, impaired differentiation into T helper 1 (Th1) and Th2 cells without diversion into FoxP3(+) status or substantial effect on Th17 cell differentiation. mTORC2 promoted phosphorylation of protein kinase B (PKB, or Akt) and PKC, Akt activity, and nuclear NF-kappaB transcription factors in response to T cell activation. Complementation with active Akt restored only T-bet transcription factor expression and Th1 cell differentiation, whereas activated PKC-theta reverted only GATA3 transcription factor and the Th2 cell defect of mTORC2 mutant cells. Collectively, the data uncover vital mTOR-PKC and mTOR-Akt connections in T cell differentiation and reveal distinct pathways by which mTORC2 regulates development of Th1 and Th2 cell subsets. 10.1016/j.immuni.2010.06.002
    Gut-residing segmented filamentous bacteria drive autoimmune arthritis via T helper 17 cells. Wu Hsin-Jung,Ivanov Ivaylo I,Darce Jaime,Hattori Kimie,Shima Tatsuichiro,Umesaki Yoshinori,Littman Dan R,Benoist Christophe,Mathis Diane Immunity Commensal microbes can have a substantial impact on autoimmune disorders, but the underlying molecular and cellular mechanisms remain largely unexplored. We report that autoimmune arthritis was strongly attenuated in the K/BxN mouse model under germ-free (GF) conditions, accompanied by reductions in serum autoantibody titers, splenic autoantibody-secreting cells, germinal centers, and the splenic T helper 17 (Th17) cell population. Neutralization of interleukin-17 prevented arthritis development in specific-pathogen-free K/BxN mice resulting from a direct effect of this cytokine on B cells to inhibit germinal center formation. The systemic deficiencies of the GF animals reflected a loss of Th17 cells from the small intestinal lamina propria. Introduction of a single gut-residing species, segmented filamentous bacteria, into GF animals reinstated the lamina propria Th17 cell compartment and production of autoantibodies, and arthritis rapidly ensued. Thus, a single commensal microbe, via its ability to promote a specific Th cell subset, can drive an autoimmune disease. 10.1016/j.immuni.2010.06.001
    IL-6 and PD-L1 antibody blockade combination therapy reduces tumour progression in murine models of pancreatic cancer. Mace Thomas A,Shakya Reena,Pitarresi Jason R,Swanson Benjamin,McQuinn Christopher W,Loftus Shannon,Nordquist Emily,Cruz-Monserrate Zobeida,Yu Lianbo,Young Gregory,Zhong Xiaoling,Zimmers Teresa A,Ostrowski Michael C,Ludwig Thomas,Bloomston Mark,Bekaii-Saab Tanios,Lesinski Gregory B Gut OBJECTIVE:Limited efficacy of immune checkpoint inhibitors in pancreatic ductal adenocarcinoma (PDAC) has prompted investigation into combination therapy. We hypothesised that interleukin 6 (IL-6) blockade would modulate immunological features of PDAC and enhance the efficacy of anti-programmed death-1-ligand 1 (PD-L1) checkpoint inhibitor therapy. DESIGN:Transcription profiles and IL-6 secretion from primary patient-derived pancreatic stellate cells (PSCs) were analyzed via Nanostring and immunohistochemistry, respectively. In vivo efficacy and mechanistic studies were conducted with antibodies (Abs) targeting IL-6, PD-L1, CD4 or CD8 in subcutaneous or orthotopic models using Panc02, MT5 or KPC-luc cell lines; and the aggressive, genetically engineered PDAC model (Kras, Trp53, Pdx1-cre, Brca2 (KPC-Brca2 mice)). Systemic and local changes in immunophenotype were measured by flow cytometry or immunohistochemical analysis. RESULTS:PSCs (n=12) demonstrated prominent IL-6 expression, which was localised to stroma of tumours. Combined IL-6 and PD-L1 blockade elicited efficacy in mice bearing subcutaneous MT5 (p<0.02) and Panc02 tumours (p=0.046), which was accompanied by increased intratumoural effector T lymphocytes (CD62LCD44). CD8-depleting but not CD4-depleting Abs abrogated the efficacy of combined IL-6 and PD-L1 blockade in mice bearing Panc02 tumours (p=0.0016). This treatment combination also elicited significant antitumour activity in mice bearing orthotopic KPC-luc tumours and limited tumour progression in KPC-Brca2 mice (p<0.001). Histological analysis revealed increased T-cell infiltration and reduced α-smooth muscle actin cells in tumours from multiple models. Finally, IL-6 and PD-L1 blockade increased overall survival in KPC-Brca2 mice compared with isotype controls (p=0.0012). CONCLUSIONS:These preclinical results indicate that targeted inhibition of IL-6 may enhance the efficacy of anti-PD-L1 in PDAC. 10.1136/gutjnl-2016-311585
    MerTK expressing hepatic macrophages promote the resolution of inflammation in acute liver failure. Triantafyllou Evangelos,Pop Oltin T,Possamai Lucia A,Wilhelm Annika,Liaskou Evaggelia,Singanayagam Arjuna,Bernsmeier Christine,Khamri Wafa,Petts Gemma,Dargue Rebecca,Davies Scott P,Tickle Joseph,Yuksel Muhammed,Patel Vishal C,Abeles Robin D,Stamataki Zania,Curbishley Stuart M,Ma Yun,Wilson Ian D,Coen Muireann,Woollard Kevin J,Quaglia Alberto,Wendon Julia,Thursz Mark R,Adams David H,Weston Chris J,Antoniades Charalambos G Gut OBJECTIVE:Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response. DESIGN:Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice. RESULTS:We demonstrate a significant expansion of resolution-like MerTK+HLA-DR cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCII macrophages during the resolution phase in ALF, APAP-treated Mer mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DR phenotype which promotes neutrophil apoptosis and their subsequent clearance. CONCLUSIONS:We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury. 10.1136/gutjnl-2016-313615
    Increased peripheral CD4 regulatory T cells persist after successful direct-acting antiviral treatment of chronic hepatitis C. Langhans Bettina,Nischalke Hans Dieter,Krämer Benjamin,Hausen Annekristin,Dold Leona,van Heteren Peer,Hüneburg Robert,Nattermann Jacob,Strassburg Christian P,Spengler Ulrich Journal of hepatology BACKGROUND & AIMS:CD4 regulatory T cells (Tregs) expand during chronic hepatitis C virus (HCV) infection, inhibit antiviral immunity and promote fibrosis. Direct-acting antiviral agents (DAA) have revolutionized HCV therapy. However, it is unclear if Tregs are normalized after DAA-induced HCV elimination. METHODS:We analyzed Tregs before (baseline), at end of therapy (EOT), 12 and 24weeks (SVR12, SVR24) and long-term (51±14weeks) after EOT in 26 genotype-1-infected patients who were successfully treated with sofosbuvir (SOF) plus interferon (IFN)/ribavirin (n=12) and IFN-free DAA regimens (SOF plus daclatasvir or simeprevir; n=14). Frequency, phenotype and suppressor function of peripheral Foxp3 CD25 CD4 T cells were studied by multi-color flow cytometry and co-culture inhibition assays. RESULTS:Frequencies and activation status of Foxp3 CD25 CD4 T cells remained elevated above those of normal controls in both treatment groups even long-term after HCV elimination. Co-culture assays indicated a dose-response relationship for functional inhibition of autologous CD4 effector T cells and confirmed that activation of Tregs remained largely unchanged over the observation period. Unlike IFN-free regimens, SOF plus IFN/ribavirin induced a transiently increased frequency of Foxp3 CD25 CD4 T cells at EOT (5.0% at baseline to 6.1% at EOT; p=0.001). These Foxp3 CD25 CD4 T cells co-expressed the activation markers glycoprotein A repetitions predominant (GARP; p=0.012) and tumor necrosis factor receptor superfamily, member 4 (OX-40; p=0.001) but showed unchanged in vitro inhibitory activity. CONCLUSION:Although IFN-based DAA therapy induced transient expansion of activated Foxp3 CD25 CD4 T cells, neither IFN-based nor IFN-free DAA regimens normalized frequencies and activation status of Tregs one year after viral elimination. Persistence of immunosuppressive Tregs may thus contribute to complications of liver disease even long-term after HCV cure. LAY SUMMARY:In chronic hepatitis C virus (HCV) infection, CD4 regulatory T cells (Tregs) can reduce antiviral immune responses, promote liver fibrosis and may increase the risk for liver cancer, because they gradually expand during disease. Modern direct-acting antiviral agents (DAA) can "cure" hepatitis C in almost all treated patients. However, our study shows that DAA do not normalize the increased frequency and activation status of Tregs even long-term after HCV elimination. Tregs may persistently modulate functions of the immune system even after "cure" of hepatitis C. 10.1016/j.jhep.2016.12.019
    Apoptosis threshold set by Noxa and Mcl-1 after T cell activation regulates competitive selection of high-affinity clones. Wensveen Felix M,van Gisbergen Klaas P J M,Derks Ingrid A M,Gerlach Carmen,Schumacher Ton N,van Lier René A W,Eldering Eric Immunity The adaptive immune system generates protective T cell responses via a poorly understood selection mechanism that favors expansion of clones with optimal affinity for antigen. Here we showed that upon T cell activation, the proapoptotic molecule Noxa (encoded by Pmaip1) and its antagonist Mcl-1 were induced. During an acute immune response against influenza or ovalbumin, Pmaip1(-/-) effector T cells displayed decreased antigen affinity and functionality. Molecular analysis of influenza-specific T cells revealed persistence of many subdominant clones in the Pmaip1(-/-) effector pool. When competing for low-affinity antigen, Pmaip1(-/-) TCR transgenic T cells had a survival advantage in vitro, resulting in increased numbers of effector cells in vivo. Mcl-1 protein stability was controlled by T cell receptor (TCR) affinity-dependent interleukin-2 signaling. These results establish a role for apoptosis early during T cell expansion, based on antigen-driven competition and survival of the fittest T cells. 10.1016/j.immuni.2010.06.005
    Interleukin-1beta selectively expands and sustains interleukin-22+ immature human natural killer cells in secondary lymphoid tissue. Hughes Tiffany,Becknell Brian,Freud Aharon G,McClory Susan,Briercheck Edward,Yu Jianhua,Mao Charlene,Giovenzana Chiara,Nuovo Gerard,Wei Lai,Zhang Xiaoli,Gavrilin Mikhail A,Wewers Mark D,Caligiuri Michael A Immunity Among human natural killer (NK) cell intermediates in secondary lymphoid tissue (SLT), stage 3 CD34(-)CD117(+)CD161(+)CD94(-) immature NK (iNK) cells uniquely express aryl hydrocarbon receptor (AHR) and interleukin-22 (IL-22), supporting a role in mucosal immunity. The mechanisms controlling proliferation and differentiation of these cells are unknown. Here we demonstrate that the IL-1 receptor IL-1R1 was selectively expressed by a subpopulation of iNK cells that localized proximal to IL-1beta-producing conventional dendritic cells (cDCs) within SLT. IL-1R1(hi) iNK cells required continuous exposure to IL-1beta to retain AHR and IL-22 expression, and they proliferate in direct response to cDC-derived IL-15 and IL-1beta. In the absence of IL-1beta, a substantially greater fraction of IL-1R1(hi) iNK cells differentiated to stage 4 NK cells and acquired the ability to kill and secrete IFN-gamma. Thus, cDC-derived IL-1beta preserves and expands IL-1R1(hi)IL-22(+)AHR(+) iNK cells, potentially influencing human mucosal innate immunity during infection. 10.1016/j.immuni.2010.06.007
    Liver sinusoidal endothelial cell cross-priming is supported by CD4 T cell-derived IL-2. Wittlich Michaela,Dudek Michael,Böttcher Jan P,Schanz Oliver,Hegenbarth Silke,Bopp Tobias,Schmitt Edgar,Kurts Christian,Garbers Christoph,Rose John Stefan,Knolle Percy A,Wohlleber Dirk Journal of hepatology BACKGROUND & AIMS:Liver sinusoidal endothelial cells (LSECs) are prominent liver-resident antigen (cross-)presenting cells. LSEC cross-priming of naïve CD8 T cells does not require CD4 T cell help in contrast to priming by dendritic cells (DC) but leads to the formation of memory T cells that is preceded by transient Granzyme B (GzmB) expression. Here we provide evidence for a so far unrecognized CD4 T helper cell function in LSEC-induced CD8 T cell activation. METHODS:Naïve CD8 T cells and differentiated T helper 1 (T1) cells were stimulated by antigen-presenting LSEC, and GzmB expression in CD8 T cells was determined by flow cytometry. To identify molecular pathways mediating this GzmB expression, mechanistic proof-of-concept experiments were conducted using stimulatory anti-CD3 antibody together with Hyper-IL-6. RESULTS:We demonstrate that LSECs simultaneously function in antigen co-presentation to CD8 and CD4 T cells. Such co-presentation revealed a function of T1 cells to increase GzmB expression in CD8 T cells after LSEC but not DC cross-priming. IL-2 released from T1 cells was required but not sufficient for rapid GzmB induction in CD8 T cells. T cell receptor together with IL-6 trans-signaling was necessary for IL-2 to mediate rapid GzmB induction. CONCLUSIONS:Our findings indicate that LSECs can serve as a platform to facilitate CD4-CD8 T cell crosstalk enhancing the immune function of LSECs to cross-prime CD8 T cells. IL-6 trans-signaling-mediated responsiveness for IL-2 inducing sustained GzmB expression in CD8 T cells reveals unique mechanisms of CD4 T cell help and CD8 T cell differentiation through liver-resident antigen-presenting cells. LAY SUMMARY:Our findings demonstrate that LSEC co-present antigen to CD8 and CD4 T cells and thereby enable CD4 T cell help for LSEC-priming of CD8 T cells. This CD4 T cell help selectively enhances the rapid upregulation of GzmB and effector function of LSEC-primed CD8 T cells thereby enhancing functional differentiation towards CD8 effector T cells. 10.1016/j.jhep.2016.12.015
    Secreted nuclear protein DEK regulates hematopoiesis through CXCR2 signaling. Capitano Maegan L,Mor-Vaknin Nirit,Saha Anjan K,Cooper Scott,Legendre Maureen,Guo Haihong,Contreras-Galindo Rafael,Kappes Ferdinand,Sartor Maureen A,Lee Christopher T,Huang Xinxin,Markovitz David M,Broxmeyer Hal E The Journal of clinical investigation The nuclear protein DEK is an endogenous DNA-binding chromatin factor regulating hematopoiesis. DEK is one of only 2 known secreted nuclear chromatin factors, but whether and how extracellular DEK regulates hematopoiesis is not known. We demonstrated that extracellular DEK greatly enhanced ex vivo expansion of cytokine-stimulated human and mouse hematopoietic stem cells (HSCs) and regulated HSC and hematopoietic progenitor cell (HPC) numbers in vivo and in vitro as determined both phenotypically (by flow cytometry) and functionally (through transplantation and colony formation assays). Recombinant DEK increased long-term HSC numbers and decreased HPC numbers through a mechanism mediated by the CXC chemokine receptor CXCR2 and heparan sulfate proteoglycans (HSPGs) (as determined utilizing Cxcr2-/- mice, blocking CXCR2 antibodies, and 3 different HSPG inhibitors) that was associated with enhanced phosphorylation of ERK1/2, AKT, and p38 MAPK. To determine whether extracellular DEK required nuclear function to regulate hematopoiesis, we utilized 2 mutant forms of DEK: one that lacked its nuclear translocation signal and one that lacked DNA-binding ability. Both altered HSC and HPC numbers in vivo or in vitro, suggesting the nuclear function of DEK is not required. Thus, DEK acts as a hematopoietic cytokine, with the potential for clinical applicability. 10.1172/JCI127460
    Differential immune profiles distinguish the mutational subtypes of gastrointestinal stromal tumor. Vitiello Gerardo A,Bowler Timothy G,Liu Mengyuan,Medina Benjamin D,Zhang Jennifer Q,Param Nesteene J,Loo Jennifer K,Goldfeder Rachel L,Chibon Frederic,Rossi Ferdinand,Zeng Shan,DeMatteo Ronald P The Journal of clinical investigation Gastrointestinal stromal tumor (GIST) is the most common human sarcoma, frequently characterized by an oncogenic mutation in the KIT or platelet-derived growth factor receptor alpha (PDGFRA) genes. We performed RNA sequencing of 75 human GIST tumors from 75 patients, comprising the largest cohort of GISTs sequenced to date, in order to discover differences in the immune infiltrates of KIT and PDGFRA-mutant GIST. Through bioinformatics, immunohistochemistry, and flow cytometry, we found that PDGFRA-mutant GISTs harbored more immune cells with increased cytolytic activity when compared to KIT-mutant GISTs. PDGFRA-mutant GISTs expressed many chemokines, such as CXCL14, at a significantly higher level when compared to KIT-mutant GISTs and exhibited more diverse driver-derived neoepitope:HLA binding, both of which may contribute to PDGFRA-mutant GIST immunogenicity. Through machine learning, we generated gene expression-based immune profiles capable of differentiating KIT and PDGFRA-mutant GISTs, and also identified additional immune features of high PD-1 and PD-L1 expressing tumors across all GIST mutational subtypes, which may provide insight into immunotherapeutic opportunities and limitations in GIST. 10.1172/JCI124108
    Astrocytes Resist HIV-1 Fusion but Engulf Infected Macrophage Material. Russell Rebecca A,Chojnacki Jakub,Jones Daniel M,Johnson Errin,Do Thao,Eggeling Christian,Padilla-Parra Sergi,Sattentau Quentin J Cell reports HIV-1 disseminates to diverse tissues and establishes long-lived viral reservoirs. These reservoirs include the CNS, in which macrophage-lineage cells, and as suggested by many studies, astrocytes, may be infected. Here, we have investigated astrocyte infection by HIV-1. We confirm that astrocytes trap and internalize HIV-1 particles for subsequent release but find no evidence that these particles infect the cell. Astrocyte infection was not observed by cell-free or cell-to-cell routes using diverse approaches, including luciferase and GFP reporter viruses, fixed and live-cell fusion assays, multispectral flow cytometry, and super-resolution imaging. By contrast, we observed intimate interactions between HIV-1-infected macrophages and astrocytes leading to signals that might be mistaken for astrocyte infection using less stringent approaches. These results have implications for HIV-1 infection of the CNS, viral reservoir formation, and antiretroviral therapy. 10.1016/j.celrep.2017.01.027
    Modulating Phagocytic Cell Sequestration by Tailoring Nanoconstruct Softness. Palomba Roberto,Palange Anna Lisa,Rizzuti Ilaria Francesca,Ferreira Miguel,Cervadoro Antonio,Barbato Maria Grazia,Canale Claudio,Decuzzi Paolo ACS nano The effect of nanoparticle size, shape, and surface properties on cellular uptake has been extensively investigated for its basic science and translational implications. Recently, softness is emerging as a design parameter for modulating the interaction of nanoparticles with cells and the biological microenvironment. Here, circular, quadrangular, and elliptical polymeric nanoconstructs of different sizes are realized with a Young's modulus ranging from ∼100 kPa (soft) to 10 MPa (rigid). The interaction of these nanoconstructs with professional phagocytic cells is assessed via confocal microscopy and flow cytometry analyses. Regardless of the size and shape, softer nanoconstructs evade cellular uptake up to 5 times more efficiently, by bone-marrow-derived monocytes, as compared to rigid nanoconstructs. Soft circular and quadrangular nanoconstructs are equally uptaken by professional phagocytic cells (<15%); soft elliptical particles are more avidly internalized (<60%) possibly because of the larger size and elongated shape, whereas over 70% of rigid nanoconstructs of any shape and size are uptaken. Inhibition of actin polymerization via cytochalasin D reduces the internalization propensity for all nanoconstruct types. High-resolution live cell microscopy documents that soft nanoconstructs mostly establish short-lived (<30 s) interactions with macrophages, thus diminishing the likelihood of recognition and internalization. The bending stiffness is identified as a discriminating factor for internalization, whereby particles with a bending stiffness slightly higher than cells would more efficiently oppose internalization as compared to stiffer or softer particles. These results confirm that softness is a key parameter in modulating the behavior of nanoparticles and are expected to inspire the design of more efficient nanoconstructs for drug delivery, biomedical imaging, and immunomodulatory therapies. 10.1021/acsnano.7b07797
    Reinduction platform for children with first marrow relapse of acute lymphoblastic Leukemia: A Children's Oncology Group Study[corrected]. Raetz Elizabeth A,Borowitz Michael J,Devidas Meenakshi,Linda Stephen B,Hunger Stephen P,Winick Naomi J,Camitta Bruce M,Gaynon Paul S,Carroll William L Journal of clinical oncology : official journal of the American Society of Clinical Oncology PURPOSE:Treatment of childhood relapsed acute lymphoblastic leukemia (ALL) remains a significant challenge. The goal of the Children's Oncology Group (COG) AALL01P2 study was to develop a safe and active chemotherapy reinduction platform, which could be used to evaluate novel agents in future trials. PATIENTS AND METHODS:One hundred twenty-four patients with ALL and first marrow relapse received three, 35-day blocks of reinduction chemotherapy: 69 with early relapse (ER; < 36 months from initial diagnosis) and 55 with late relapse (LR). Minimal residual disease (MRD) was measured by flow cytometry after each treatment block. RESULTS:Second complete remission (CR2) rates at the end of block 1 in 117 assessable patients were 68% +/- 6% for ER (n = 63) and 96% +/- 3% for LR (n = 54; P < .0001). Five of seven patients with T-cell ALL (T-ALL) failed to achieve CR2. Among patients in CR2, MRD greater than 0.01% was detected at the end of block 1 in 75% +/- 7% of ER (n = 36) versus 51% +/- 8% of LR (n = 43; P = .0375) and 12-month event-free survival was 80% +/- 7% versus 58% +/- 7% in MRD-negative versus positive patients (P < .0005). Blocks 2 and 3 of therapy resulted in reduction of MRD burden in 40 of 56 patients who were MRD positive after block 1. Toxicity was acceptable during all three blocks with five deaths (4%) from infections. CONCLUSION:The AALL01P2 regimen is a tolerable and active reinduction platform, suitable for testing in combination with novel agents in B-precursor ALL. Alternative strategies are needed for T-ALL. Serial MRD measurements were feasible and prognostic of outcome. 10.1200/JCO.2008.16.1414
    Chemistry and biology in femtoliter and picoliter volume droplets. Chiu Daniel T,Lorenz Robert M Accounts of chemical research The basic unit of any biological system is the cell, and malfunctions at the single-cell level can result in devastating diseases; in cancer metastasis, for example, a single cell seeds the formation of a distant tumor. Although tiny, a cell is a highly heterogeneous and compartmentalized structure: proteins, lipids, RNA, and small-molecule metabolites constantly traffic among intracellular organelles. Gaining detailed information about the spatiotemporal distribution of these biomolecules is crucial to our understanding of cellular function and dysfunction. To access this information, we need sensitive tools that are capable of extracting comprehensive biochemical information from single cells and subcellular organelles. In this Account, we outline our approach and highlight our progress toward mapping the spatiotemporal organization of information flow in single cells. Our technique is centered on the use of femtoliter- and picoliter-sized droplets as nanolabs for manipulating single cells and subcellular compartments. We have developed a single-cell nanosurgical technique for isolating select subcellular structures from live cells, a capability that is needed for the high-resolution manipulation and chemical analysis of single cells. Our microfluidic approaches for generating single femtoliter-sized droplets on demand include both pressure and electric field methods; we have also explored a design for the on-demand generation of multiple aqueous droplets to increase throughput. Droplet formation is only the first step in a sequence that requires manipulation, fusion, transport, and analysis. Optical approaches provide the most convenient and precise control over the formed droplets with our technology platform; we describe aqueous droplet manipulation with optical vortex traps, which enable the remarkable ability to dynamically "tune" the concentration of the contents. Integration of thermoelectric manipulations with these techniques affords further control. The amount of chemical information that can be gleaned from single cells and organelles is critically dependent on the methods available for analyzing droplet contents. We describe three techniques we have developed: (i) droplet encapsulation, rapid cell lysis, and fluorescence-based single-cell assays, (ii) physical sizing of the subcellular organelles and nanoparticles in droplets, and (iii) capillary electrophoresis (CE) analysis of droplet contents. For biological studies, we are working to integrate the different components of our technology into a robust, automated device; we are also addressing an anticipated need for higher throughput. With progress in these areas, we hope to cement our technique as a new tool for studying single cells and organelles with unprecedented molecular detail. 10.1021/ar8002464
    Defective cholesterol metabolism in haematopoietic stem cells promotes monocyte-driven atherosclerosis in rheumatoid arthritis. Dragoljevic Dragana,Kraakman Michael J,Nagareddy Prabhakara R,Ngo Devi,Shihata Waled,Kammoun Helene L,Whillas Alexandra,Lee Man Kit Sam,Al-Sharea Annas,Pernes Gerard,Flynn Michelle C,Lancaster Graeme I,Febbraio Mark A,Chin-Dusting Jaye,Hanaoka Beatriz Y,Wicks Ian P,Murphy Andrew J European heart journal Aim:Rheumatoid arthritis (RA) is associated with an approximately two-fold elevated risk of cardiovascular (CV)-related mortality. Patients with RA present with systemic inflammation including raised circulating myeloid cells, but fail to display traditional CV risk-factors, particularly dyslipidaemia. We aimed to explore if increased circulating myeloid cells is associated with impaired atherosclerotic lesion regression or altered progression in RA. Methods and results:Using flow cytometry, we noted prominent monocytosis, neutrophilia, and thrombocytosis in two mouse models of RA. This was due to enhanced proliferation of the haematopoietic stem and progenitor cells (HSPCs) in the bone marrow and the spleen. HSPCs expansion was associated with an increase in the cholesterol content, due to a down-regulation of cholesterol efflux genes, Apoe, Abca1, and Abcg1. The HSPCs also had enhanced expression of key myeloid promoting growth factor receptors. Systemic inflammation was found to cause defective cellular cholesterol metabolism. Increased myeloid cells in mice with RA were associated with a significant impairment in lesion regression, even though cholesterol levels were equivalent to non-arthritic mice. Lesions from arthritic mice exhibited a less stable phenotype as demonstrated by increased immune cell infiltration, lipid accumulation, and decreased collagen formation. In a progression model, we noted monocytosis, enhanced monocytes recruitment to lesions, and increased plaque macrophages. This was reversed with administration of reconstituted high-density lipoprotein (rHDL). Furthermore, RA patients have expanded CD16+ monocyte subsets and a down-regulation of ABCA1 and ABCG1. Conclusion:Rheumatoid arthritis impairs atherosclerotic regression and alters progression, which is associated with an expansion of myeloid cells and disturbed cellular cholesterol handling, independent of plasma cholesterol levels. Infusion of rHDL prevented enhanced myelopoiesis and monocyte entry into lesions. Targeting cellular cholesterol defects in people with RA, even if plasma cholesterol is within the normal range, may limit vascular disease. 10.1093/eurheartj/ehy119
    Plasma Cell Polarization to the Immunoglobulin G Phenotype in Hepatocellular Carcinomas Involves Epigenetic Alterations and Promotes Hepatoma Progression in Mice. Wei Yuan,Lao Xiang-Ming,Xiao Xiao,Wang Xu-Yan,Wu Zong-Jian,Zeng Qiu-Hui,Wu Cai-Yuan,Wu Rui-Qi,Chen Zhen-Xin,Zheng Limin,Li Bo,Kuang Dong-Ming Gastroenterology BACKGROUND & AIMS:Little is known about the composition and generation of plasma cell subsets in patients with hepatocellular carcinoma (HCC) and how these associate with outcomes. We investigated whether, or how, plasma cells differentiate and function in patients with HCC and mice with liver tumors. METHODS:We analyzed subset composition and distribution of plasma cells in HCC samples from 342 patients who underwent curative resection at the Cancer Center of Sun Yat-sen University in China; samples of non-tumor liver tissue were used as controls. We associated plasma cell profiles with patient outcomes. Tissue-derived leukocytes were analyzed by flow cytometry and real-time polymerase chain reaction. The ability of macrophages to regulate plasma cell differentiation was determined in ex vivo cultures of cells from human HCC tissues. C57BL/6 and BALB/c mice were given injections of Hepa1-6 cells, which formed hepatomas, or H22 cells, which formed ascitic hepatomas. Gene expression patterns were analyzed in human HCC, mouse hepatoma, and non-tumor tissues by real-time polymerase chain reaction. Mice with hepatomas were given injections of GSK126 (an inhibitor of histone H3 lysine 27 methyltransferase [EZH2]) and 5-AZA-dC (an inhibitor of DNA methyltransferases); tumor tissues were analyzed by immunofluorescence and immunohistochemistry for the presence of immune cells and cytokines. RESULTS:B cells isolated from HCCs had somatic hypermutations and class-switch recombinations to the IgG phenotype that were not observed in non-tumor tissues. Increased level of plasma cells correlated with poor outcomes of patients. Activated CD4 T cells from HCCs stimulated C-X-C motif chemokine 10 (CXCL10) production by macrophages. CXCL10 bound CXC chemokine receptor 3 on B cells and signaled via extracellular signal-regulated kinase to cause them to become IgG-producing plasma cells. IgG activated Fc receptors on macrophages and induced them to produce interleukin 6, interleukin 10, and C-C motif chemokine ligand 20 (CCL20). In mice with hepatomas, depletion of B cells prevented generation of these macrophage, increased the anti-tumor T cell response, and reduced growth of hepatomas. However, these effects were lost after injection of CXC chemokine receptor 3-positive plasma cells. Human HCC and mouse hepatoma tissues had increased expression of DNA methyltransferase 1 and EZH2 compared with non-tumor tissues. Injection of mice with GSK126 and 5-AZA-dC induced expression of CXCL10 by tumor cells and caused plasma cell polarization, suppression of the anti-tumor T cell response, and hepatoma growth. CONCLUSIONS:Human HCC tissues contain B cells with class-switch recombinations to the IgG phenotype. Activated CD4 T cells from HCCs stimulate CXCL10 production by macrophages; CXCL10 binds CXC chemokine receptor 3 on B cells and causes them to become IgG-producing plasma cells. IgG activates Fc receptor in macrophages to produce cytokines that reduce the anti-tumor immune response. In mice with hepatomas, depletion of B cells prevented generation of these macrophages, increased the anti-tumor T cell response, and reduced growth of hepatomas. This pathway involves increased expression of DNA methyltransferase 1 and EZH2 by HCC and hepatoma cells. 10.1053/j.gastro.2019.01.250
    Directed differentiation of human embryonic stem cells into functional retinal pigment epithelium cells. Idelson Maria,Alper Ruslana,Obolensky Alexey,Ben-Shushan Etti,Hemo Itzhak,Yachimovich-Cohen Nurit,Khaner Hanita,Smith Yoav,Wiser Ofer,Gropp Michal,Cohen Malkiel A,Even-Ram Sharona,Berman-Zaken Yael,Matzrafi Limor,Rechavi Gideon,Banin Eyal,Reubinoff Benjamin Cell stem cell Dysfunction and loss of retinal pigment epithelium (RPE) leads to degeneration of photoreceptors in age-related macular degeneration and subtypes of retinitis pigmentosa. Human embryonic stem cells (hESCs) may serve as an unlimited source of RPE cells for transplantation in these blinding conditions. Here we show the directed differentiation of hESCs toward an RPE fate under defined culture conditions. We demonstrate that nicotinamide promotes the differentiation of hESCs to neural and subsequently to RPE fate. In the presence of nicotinamide, factors from the TGF-beta superfamily, which presumably pattern RPE development during embryogenesis, further direct RPE differentiation. The hESC-derived pigmented cells exhibit the morphology, marker expression, and function of authentic RPE and rescue retinal structure and function after transplantation to an animal model of retinal degeneration caused by RPE dysfunction. These results are an important step toward the future use of hESCs to replenish RPE in blinding diseases. 10.1016/j.stem.2009.07.002
    DNA methyltransferase 1 is essential for and uniquely regulates hematopoietic stem and progenitor cells. Trowbridge Jennifer J,Snow Jonathan W,Kim Jonghwan,Orkin Stuart H Cell stem cell DNA methylation is essential for development and in diverse biological processes. The DNA methyltransferase Dnmt1 maintains parental cell methylation patterns on daughter DNA strands in mitotic cells; however, the precise role of Dnmt1 in regulation of quiescent adult stem cells is not known. To examine the role of Dnmt1 in adult hematopoietic stem cells (HSCs), we conditionally disrupted Dnmt1 in the hematopoietic system. Defects were observed in Dnmt1-deficient HSC self-renewal, niche retention, and in the ability of Dnmt1-deficient HSCs to give rise to multilineage hematopoiesis. Loss of Dnmt1 also had specific impact on myeloid progenitor cells, causing enhanced cell cycling and inappropriate expression of mature lineage genes. Dnmt1 regulates distinct patterns of methylation and expression of discrete gene families in long-term HSCs and multipotent and lineage-restricted progenitors, suggesting that Dnmt1 differentially controls these populations. These findings establish a unique and critical role for Dnmt1 in the primitive hematopoietic compartment. 10.1016/j.stem.2009.08.016
    Interferon-λ mediates oral tolerance and inhibits antigen-specific, T-helper 2 cell-mediated inflammation in mouse intestine. He Shao-Heng,Chen Xiao,Song Chun-Hua,Liu Zhi-Qiang,Zhou Lin-Fu,Ma Wen-Jing,Zhao Lei-Di,Li Tong-Li,Tang Shang-Guo,Xing Zhou,Yang Ping-Chang Gastroenterology BACKGROUND & AIMS:Oral tolerance is an important component of gastrointestinal homeostasis, but mechanisms of its development are not fully understood. Loss of oral tolerance occurs during food allergen-related inflammation in the gastrointestinal tract. Interferon (IFN)-λ regulates immunity, but its role in oral tolerance is not clear. We investigated the role and the mechanism of IFN-λ in the development of oral tolerance and its effect on antigen-induced, T-helper (Th)-2 cell-mediated inflammation in the intestine. METHODS:Expression of IFN-λ and its receptor were analyzed by immunohistochemical, flow cytometric, or immunoblot analyses. Tolerogenic dendritic cells (DCs) and regulatory T cells were examined in vitro and in vivo. A mouse model of antigen-induced, Th2 cell-mediated intestinal inflammation was used to examine the role of IFN-λ and T cells in oral tolerance in the intestine. RESULTS:CD3+ cells expressed the IFN-λ receptor, which was up-regulated following antigen-specific or nonspecific activation. Interaction between IFN-λ and its receptor induced apoptosis of T cells and their subsequent phagocytosis by DCs. This led to the generation of tolerogenic DCs and T regulatory cells in vitro and in vivo. Passive transfer of IFN-λ-primed CD3+ cells inhibited Th2 cell-mediated inflammation in the intestine. CONCLUSIONS:IFN-λ is involved in development and maintenance of oral tolerance in the intestines of mice; it might be used to suppress antigen-specific Th2 cell-mediated inflammation in patients. 10.1053/j.gastro.2011.04.006
    Human placenta is a potent hematopoietic niche containing hematopoietic stem and progenitor cells throughout development. Robin Catherine,Bollerot Karine,Mendes Sandra,Haak Esther,Crisan Mihaela,Cerisoli Francesco,Lauw Ivoune,Kaimakis Polynikis,Jorna Ruud,Vermeulen Mark,Kayser Manfred,van der Linden Reinier,Imanirad Parisa,Verstegen Monique,Nawaz-Yousaf Humaira,Papazian Natalie,Steegers Eric,Cupedo Tom,Dzierzak Elaine Cell stem cell Hematopoietic stem cells (HSCs) are responsible for the life-long production of the blood system and are pivotal cells in hematologic transplantation therapies. During mouse and human development, the first HSCs are produced in the aorta-gonad-mesonephros region. Subsequent to this emergence, HSCs are found in other anatomical sites of the mouse conceptus. While the mouse placenta contains abundant HSCs at midgestation, little is known concerning whether HSCs or hematopoietic progenitors are present and supported in the human placenta during development. In this study we show, over a range of developmental times including term, that the human placenta contains hematopoietic progenitors and HSCs. Moreover, stromal cell lines generated from human placenta at several developmental time points are pericyte-like cells and support human hematopoiesis. Immunostaining of placenta sections during development localizes hematopoietic cells in close contact with pericytes/perivascular cells. Thus, the human placenta is a potent hematopoietic niche throughout development. 10.1016/j.stem.2009.08.020
    Intracellular cytokine optimization and standard operating procedure. Lamoreaux Laurie,Roederer Mario,Koup Richard Nature protocols We describe here a method for optimizing the use of polychromatic flow cytometry (with up to 17 fluorochromes simultaneously) in surface and intracellular staining of human T lymphocytes. We will highlight and discuss how to procedurally optimize key steps in the experimental process before an intracellular cytokine staining assay protocol is finalized. These include but are not limited to the titration of monoclonal antibodies, use of a dead-cell discriminator and 'dump' channel, selection of a cytokine secretion inhibitor, selection of fixation and permeabilization reagents, and inclusion of compensation controls. Building on this basic protocol, we then establish a polychromatic assay designed to detect five separate functions of T lymphocytes (production of three cytokines and one chemokine, and degranulation) while simultaneously identifying multiple surface markers on the responding cells. 10.1038/nprot.2006.268
    Antiangiogenic VEGFb Regulates Macrophage Polarization via S100A8/S100A9 in Peripheral Artery Disease. Ganta Vijay Chaitanya,Choi Min,Farber Charles R,Annex Brian H Circulation BACKGROUND:Atherosclerotic occlusions decrease blood flow to the lower limbs, causing ischemia and tissue loss in patients with peripheral artery disease (PAD). No effective medical therapies are currently available to induce angiogenesis and promote perfusion recovery in patients with severe PAD. Clinical trials aimed at inducing vascular endothelial growth factor (VEGF)-A levels, a potent proangiogenic growth factor to induce angiogenesis, and perfusion recovery were not successful. Alternate splicing in the exon-8 of VEGF-A results in the formation of VEGFxxxa (VEGFa) and VEGFxxxb (VEGFb) isoforms with existing literature focusing on VEGFb's role in inhibiting vascular endothelial growth factor receptor 2-dependent angiogenesis. However, we have recently shown that VEGFb blocks VEGF-A-induced endothelial vascular endothelial growth factor receptor 1 (VEGFR1) activation in ischemic muscle to impair perfusion recovery. Because macrophage-secreted VEGFb has been shown to decrease angiogenesis in peripheral artery disease, and macrophages were well known to play important roles in regulating ischemic muscle vascular remodeling, we examined the role of VEGFb in regulating macrophage function in PAD. METHODS:Femoral artery ligation and resection were used as an in vivo preclinical PAD model, and hypoxia serum starvation was used as an in vitro model for PAD. Experiments including laser-Doppler perfusion imaging, adoptive cell transfer to ischemic muscle, immunoblot analysis, ELISAs, immunostainings, flow cytometry, quantitative polymerase chain reaction analysis, and RNA sequencing were performed to determine a role of VEGFb in regulating macrophage phenotype and function in PAD. RESULTS:First, we found increased VEGFb expression with increased M1-like macrophages in PAD versus non-PAD (controls) muscle biopsies. Next, using in vitro hypoxia serum starvation, in vivo pre clinical PAD models, and adoptive transfer of VEGFb-expressing bone marrow-derived macrophages or VEGFR1 bone marrow-derived macrophages (M1-like phenotype), we demonstrate that VEGFb inhibits VEGFR1 activation to induce an M1-like phenotype that impairs ischemic muscle neovascularization. Subsequently, we found S100A8/S100A9 as VEGFR1 downstream regulators of macrophage polarization by RNA-Seq analysis of hypoxia serum starvation-VEGFR1 versus hypoxia serum starvation-VEGFR1 bone marrow-derived macrophages. CONCLUSIONS:In our current study, we demonstrate that increased VEGFb expression in macrophages induces an antiangiogenic M1-like phenotype that directly impairs angiogenesis. VEGFR1 inhibition by VEGFb results in S100A8/S100A9-mediated calcium influx to induce an M1-like phenotype that impairs ischemic muscle revascularization and perfusion recovery. 10.1161/CIRCULATIONAHA.118.034165
    Neutrophil-Derived S100A8/A9 Amplify Granulopoiesis After Myocardial Infarction. Sreejit Gopalkrishna,Abdel-Latif Ahmed,Athmanathan Baskaran,Annabathula Rahul,Dhyani Ashish,Noothi Sunil K,Quaife-Ryan Gregory A,Al-Sharea Annas,Pernes Gerard,Dragoljevic Dragana,Lal Hind,Schroder Kate,Hanaoka Beatriz Y,Raman Chander,Grant Maria B,Hudson James E,Smyth Susan S,Porrello Enzo R,Murphy Andrew J,Nagareddy Prabhakara R Circulation BACKGROUND:Myocardial infarction (MI) triggers myelopoiesis, resulting in heightened production of neutrophils. However, the mechanisms that sustain their production and recruitment to the injured heart are unclear. METHODS:Using a mouse model of the permanent ligation of the left anterior descending artery and flow cytometry, we first characterized the temporal and spatial effects of MI on different myeloid cell types. We next performed global transcriptome analysis of different cardiac cell types within the infarct to identify the drivers of the acute inflammatory response and the underlying signaling pathways. Using a combination of genetic and pharmacological strategies, we identified the sequelae of events that led to MI-induced myelopoiesis. Cardiac function was assessed by echocardiography. The association of early indexes of neutrophilia with major adverse cardiovascular events was studied in a cohort of patients with acute MI. RESULTS:Induction of MI results in rapid recruitment of neutrophils to the infarct, where they release specific alarmins, S100A8 and S100A9. These alarmins bind to the Toll-like receptor 4 and prime the nod-like receptor family pyrin domain-containing 3 inflammasome in naïve neutrophils and promote interleukin-1β secretion. The released interleukin-1β interacts with its receptor (interleukin 1 receptor type 1) on hematopoietic stem and progenitor cells in the bone marrow and stimulates granulopoiesis in a cell-autonomous manner. Genetic or pharmacological strategies aimed at disruption of S100A8/A9 and their downstream signaling cascade suppress MI-induced granulopoiesis and improve cardiac function. Furthermore, in patients with acute coronary syndrome, higher neutrophil count on admission and after revascularization correlates positively with major adverse cardiovascular disease outcomes. CONCLUSIONS:Our study provides novel evidence for the primary role of neutrophil-derived alarmins (S100A8/A9) in dictating the nature of the ensuing inflammatory response after myocardial injury. Therapeutic strategies aimed at disruption of S100A8/A9 signaling or their downstream mediators (eg, nod-like receptor family pyrin domain-containing 3 inflammasome, interleukin-1β) in neutrophils suppress granulopoiesis and may improve cardiac function in patients with acute coronary syndrome. 10.1161/CIRCULATIONAHA.119.043833
    Hepatitis C virus-induced NK cell activation causes metzincin-mediated CD16 cleavage and impaired antibody-dependent cytotoxicity. Oliviero Barbara,Mantovani Stefania,Varchetta Stefania,Mele Dalila,Grossi Giulia,Ludovisi Serena,Nuti Elisa,Rossello Armando,Mondelli Mario U Journal of hepatology BACKGROUND & AIMS:The Fc receptor family for immunoglobulin (Ig)G type III (FcγRIII, CD16) is an activating receptor on natural killer (NK) cells and an essential mediator of antibody-dependent cellular cytotoxicity (ADCC). There is only limited information on its role during chronic hepatitis C virus (HCV) infection. We studied CD16 expression in relation to NK cell functional activity in HCV-infected patients and sought mechanistic insights into virus-induced modulation. METHODS:NK cell CD16 expression and activation status were evaluated ex vivo by flow cytometry in HCV-infected patients and healthy controls (HC) as well as in vitro after co-culture with HCV-infected HuH7.5 cells. Rituximab-mediated ADCC was assessed in HC and HCV-infected patients using Daudi cells as a target. The role of metzincins in CD16 down-modulation was assessed using specific inhibitory molecules and by evaluating intracellular mRNA levels. RESULTS:HCV-infected patients exhibited increased frequencies of ex vivo activated NK cells and a concomitantly decreased NK CD16 expression, which resulted in impaired ADCC activity. Moreover, exposure of NK cells to culture-derived HCV recapitulated the ex vivo findings of decreased CD16 expression and increased NK cell activation. Importantly, blockade of metzincin-mediated shedding activity, including selective a disintegrin and metalloproteinase 17 (ADAM-17) inhibition, restored NK CD16 expression. Successful treatment with direct-acting antivirals partially improved NK ADCC function despite delayed CD16 reconstitution. CONCLUSION:Chronic HCV infection induces NK cell activation resulting in ADAM-17-dependent CD16 shedding and consequent impaired ADCC function. Altered ADCC may contribute to failure to eradicate HCV-infected hepatocytes. LAY SUMMARY:We show here that hepatitis C virus (HCV) activates natural killer (NK) lymphocytes which, as a consequence, loose their Fc receptor for IgG (CD16), an essential molecule for antibody binding. We show that this occurs through the action of enzymes named metzincins, resulting in altered NK-mediated antibody-dependent killing (ADCC) of target cells. This mechanism may contribute to HCV persistence and may represent a general phenomenon whereby some viruses can escape host's immune responses. 10.1016/j.jhep.2017.01.032
    MRC1-dependent scaling of the budding yeast DNA replication timing program. Koren Amnon,Soifer Ilya,Barkai Naama Genome research We describe the DNA replication timing programs of 14 yeast mutants with an extended S phase identified by a novel genome-wide screen. These mutants are associated with the DNA replication machinery, cell-cycle control, and dNTP synthesis and affect different parts of S phase. In 13 of the mutants, origin activation time scales with the duration of S phase. A limited number of origins become inactive in these strains, with inactive origins characterized by small replicons and distributed throughout S phase. In sharp contrast, cells deleted of MRC1, a gene implicated in replication fork stabilization and in the replication checkpoint pathway, maintained wild-type firing times despite over twofold lengthening of S phase. Numerous dormant origins were activated in this mutant. Our data suggest that most perturbations that lengthen S phase affect the entire program of replication timing, rather than a specific subset of origins, maintaining the relative order of origin firing time and delaying firing with relative proportions. Mrc1 emerges as a regulator of this robustness of the replication program. 10.1101/gr.102764.109
    Derepression of Polycomb targets during pancreatic organogenesis allows insulin-producing beta-cells to adopt a neural gene activity program. van Arensbergen Joris,García-Hurtado Javier,Moran Ignasi,Maestro Miguel Angel,Xu Xiaobo,Van de Casteele Mark,Skoudy Anouchka L,Palassini Matteo,Heimberg Harry,Ferrer Jorge Genome research The epigenome changes that underlie cellular differentiation in developing organisms are poorly understood. To gain insights into how pancreatic beta-cells are programmed, we profiled key histone methylations and transcripts in embryonic stem cells, multipotent progenitors of the nascent embryonic pancreas, purified beta-cells, and 10 differentiated tissues. We report that despite their endodermal origin, beta-cells show a transcriptional and active chromatin signature that is most similar to ectoderm-derived neural tissues. In contrast, the beta-cell signature of trimethylated H3K27, a mark of Polycomb-mediated repression, clusters with pancreatic progenitors, acinar cells and liver, consistent with the epigenetic transmission of this mark from endoderm progenitors to their differentiated cellular progeny. We also identified two H3K27 methylation events that arise in the beta-cell lineage after the pancreatic progenitor stage. One is a wave of cell-selective de novo H3K27 trimethylation in non-CpG island genes. Another is the loss of bivalent and H3K27me3-repressed chromatin in a core program of neural developmental regulators that enables a convergence of the gene activity state of beta-cells with that of neural cells. These findings reveal a dynamic regulation of Polycomb repression programs that shape the identity of differentiated beta-cells. 10.1101/gr.101709.109
    Identification of therapeutic targets for quiescent, chemotherapy-resistant human leukemia stem cells. Saito Yoriko,Kitamura Hiroshi,Hijikata Atsushi,Tomizawa-Murasawa Mariko,Tanaka Satoshi,Takagi Shinsuke,Uchida Naoyuki,Suzuki Nahoko,Sone Akiko,Najima Yuho,Ozawa Hidetoshi,Wake Atsushi,Taniguchi Shuichi,Shultz Leonard D,Ohara Osamu,Ishikawa Fumihiko Science translational medicine Human acute myeloid leukemia (AML) originates from rare leukemia stem cells (LSCs). Because these chemotherapy-resistant LSCs are thought to underlie disease relapse, effective therapeutic strategies specifically targeting these cells may be beneficial. Here, we report identification of a primary human LSC gene signature and functional characterization of human LSC-specific molecules in vivo in a mouse xenotransplantation model. In 32 of 61 (53%) patients with AML, either CD32 or CD25 or both were highly expressed in LSCs. CD32- or CD25-positive LSCs could initiate AML and were cell cycle-quiescent and chemotherapy-resistant in vivo. Normal human hematopoietic stem cells depleted of CD32- and CD25-positive cells maintained long-term multilineage hematopoietic reconstitution capacity in vivo, indicating the potential safety of treatments targeting these molecules. In addition to CD32 and CD25, quiescent LSCs within the bone marrow niche also expressed the transcription factor WT1 and the kinase HCK. These molecules are also promising targets for LSC-specific therapy. 10.1126/scitranslmed.3000349
    Platelet-derived growth factor-producing CD4+ Foxp3+ regulatory T lymphocytes promote lung fibrosis. Lo Re Sandra,Lecocq Marylène,Uwambayinema Francine,Yakoub Yousof,Delos Monique,Demoulin Jean-Baptiste,Lucas Sophie,Sparwasser Tim,Renauld Jean-Christophe,Lison Dominique,Huaux François American journal of respiratory and critical care medicine RATIONALE:There is evidence that CD4(+) effector T lymphocytes (T eff) participate in the development of lung fibrosis, but the role of their CD4(+) regulatory T-cell (T reg) counterparts remains to be determined. OBJECTIVES:To elucidate the contribution of T reg cells in a mouse model of lung fibrosis induced by silica (SiO(2)) particles. METHODS:Lung T reg and T eff cells purified from SiO(2)-treated Foxp3-GFP transgenic mice were cocultured with naive lung fibroblasts or transferred to the lungs of healthy mice. DEREG mice, which express the diphtheria toxin receptor under the control of the foxp3 gene, were used to deplete T reg cells during fibrogenesis. MEASUREMENTS AND MAIN RESULTS:CD4(+) Foxp3(+) T reg cells were persistently recruited in the lungs in response to SiO(2). T reg accumulation paralleled the establishment of pulmonary immunosuppression and fibrosis. T reg cells highly expressed platelet-derived growth factor (PDGF)-B via a TGF-β autocrine signaling pathway, directly stimulated fibroblast proliferation in vitro, and increased lung collagen deposition upon transfer in the lung of naive mice. The direct profibrotic effects of T reg cells were abolished by the inhibitor of the PDGF-B/TGF-β signaling pathway, imatinib mesylate. Neutralization of T reg-immunosuppressive activity resulted in enhanced accumulation of T eff cells and IL-4-driven pulmonary fibrogenesis, further demonstrating that T reg cells control T eff cell functions during inflammatory fibrosis. CONCLUSIONS:Our study indicates that T reg cells contribute to lung fibrosis by stimulating fibroblasts through the secretion of PDGF-B in noninflammatory conditions and regulate detrimental T eff cell activities during inflammation-related fibrosis. 10.1164/rccm.201103-0516OC
    Acute pulmonary embolism and dysfunction of CD3+ CD8+ T cell immunity. Wang Lemin,Song Haoming,Gong Zhu,Duan Qianglin,Liang Aibin American journal of respiratory and critical care medicine 10.1164/ajrccm.184.11.1315
    Proinflammatory cytokine signaling required for the generation of natural killer cell memory. Sun Joseph C,Madera Sharline,Bezman Natalie A,Beilke Joshua N,Kaplan Mark H,Lanier Lewis L The Journal of experimental medicine Although natural killer (NK) cells are classified as innate immune cells, recent studies demonstrate that NK cells can become long-lived memory cells and contribute to secondary immune responses. The precise signals that promote generation of long-lived memory NK cells are unknown. Using cytokine receptor-deficient mice, we show that interleukin-12 (IL-12) is indispensible for mouse cytomegalovirus (MCMV)-specific NK cell expansion and generation of memory NK cells. In contrast to wild-type NK cells that proliferated robustly and resided in lymphoid and nonlymphoid tissues for months after MCMV infection, IL-12 receptor-deficient NK cells failed to expand and were unable to mediate protection after MCMV challenge. We further demonstrate that a STAT4-dependent IFN-γ-independent mechanism contributes toward the generation of memory NK cells during MCMV infection. Understanding the full contribution of inflammatory cytokine signaling to the NK cell response against viral infection will be of interest for the development of vaccines and therapeutics. 10.1084/jem.20111760